Science.gov

Sample records for environment electron transport

  1. A Deterministic Transport Code for Space Environment Electrons

    NASA Technical Reports Server (NTRS)

    Nealy, John E.; Chang, C. K.; Norman, Ryan B.; Blattnig, Steve R.; Badavi, Francis F.; Adamczyk, Anne M.

    2010-01-01

    A deterministic computational procedure has been developed to describe transport of space environment electrons in various shield media. This code is an upgrade and extension of an earlier electron code. Whereas the former code was formulated on the basis of parametric functions derived from limited laboratory data, the present code utilizes well established theoretical representations to describe the relevant interactions and transport processes. The shield material specification has been made more general, as have the pertinent cross sections. A combined mean free path and average trajectory approach has been used in the transport formalism. Comparisons with Monte Carlo calculations are presented.

  2. A Deterministic Computational Procedure for Space Environment Electron Transport

    NASA Technical Reports Server (NTRS)

    Nealy, John E.; Chang, C. K.; Norman, Ryan B.; Blattnig, Steve R.; Badavi, Francis F.; Adamcyk, Anne M.

    2010-01-01

    A deterministic computational procedure for describing the transport of electrons in condensed media is formulated to simulate the effects and exposures from spectral distributions typical of electrons trapped in planetary magnetic fields. The primary purpose for developing the procedure is to provide a means of rapidly performing numerous repetitive transport calculations essential for electron radiation exposure assessments for complex space structures. The present code utilizes well-established theoretical representations to describe the relevant interactions and transport processes. A combined mean free path and average trajectory approach is used in the transport formalism. For typical space environment spectra, several favorable comparisons with Monte Carlo calculations are made which have indicated that accuracy is not compromised at the expense of the computational speed.

  3. Transport of Space Environment Electrons: A Simplified Rapid-Analysis Computational Procedure

    NASA Technical Reports Server (NTRS)

    Nealy, John E.; Anderson, Brooke M.; Cucinotta, Francis A.; Wilson, John W.; Katz, Robert; Chang, C. K.

    2002-01-01

    A computational procedure for describing transport of electrons in condensed media has been formulated for application to effects and exposures from spectral distributions typical of electrons trapped in planetary magnetic fields. The procedure is based on earlier parameterizations established from numerous electron beam experiments. New parameterizations have been derived that logically extend the domain of application to low molecular weight (high hydrogen content) materials and higher energies (approximately 50 MeV). The production and transport of high energy photons (bremsstrahlung) generated in the electron transport processes have also been modeled using tabulated values of photon production cross sections. A primary purpose for developing the procedure has been to provide a means for rapidly performing numerous repetitive calculations essential for electron radiation exposure assessments for complex space structures. Several favorable comparisons have been made with previous calculations for typical space environment spectra, which have indicated that accuracy has not been substantially compromised at the expense of computational speed.

  4. Effect of strain, thickness, and local surface environment on electron transport properties of oxygen-terminated copper thin films

    NASA Astrophysics Data System (ADS)

    Sanchez-Soares, Alfonso; Jones, Sarah L. T.; Plombon, John J.; Kaushik, Ananth P.; Nagle, Roger E.; Clarke, James S.; Greer, James C.

    2016-10-01

    Electron transport is studied in surface oxidized single-crystal copper thin films with a thickness of up to 5.6 nm by applying density functional theory and density functional tight binding methods to determine electron transport properties within the ballistic regime. The variation of the electron transmission as a function of film thickness as well as the different contributions to the overall electron transmission as a function of depth into the the films is examined. Transmission at the oxidized copper film surfaces is found to be universally low. Films with thickness greater than 2.7 nm exhibit a similar behavior in local transmission per unit area with depth from the film surface; transmission per unit area initially increases rapidly and then plateaus at a depth of approximately 0.35-0.5 nm away from the surface, dependent on surface facet. Unstrained films tend to exhibit a higher transmission per unit area than corresponding films under tensile strain.

  5. Biological Electron Transport Systems

    PubMed Central

    Cowan, Dwaine O.; Pasternak, Gavril; Kaufman, Frank

    1970-01-01

    The solid-state electrical conductivities of a number of ferredoxin model compounds are reported. For one of these compounds, (KFeS2)n, an electron transfer rate for a 25 Å unit is shown to be at least 1 × 108 electrons sec-1. The rate becomes proportionally larger for smaller molecular units. This rapid rate is consistant with a short pipe model for electron transport between two reaction sites. Some of the factors leading to this rapid transfer rate are considered. PMID:5269247

  6. Electronics for Extreme Environments

    NASA Technical Reports Server (NTRS)

    Patel, J. U.; Cressler, J.; Li, Y.; Niu, G.

    2001-01-01

    Most of the NASA missions involve extreme environments comprising radiation and low or high temperatures. Current practice of providing friendly ambient operating environment to electronics costs considerable power and mass (for shielding). Immediate missions such as the Europa orbiter and lander and Mars landers require the electronics to perform reliably in extreme conditions during the most critical part of the mission. Some other missions planned in the future also involve substantial surface activity in terms of measurements, sample collection, penetration through ice and crust and the analysis of samples. Thus it is extremely critical to develop electronics that could reliably operate under extreme space environments. Silicon On Insulator (SOI) technology is an extremely attractive candidate for NASA's future low power and high speed electronic systems because it offers increased transconductance, decreased sub-threshold slope, reduced short channel effects, elimination of kink effect, enhanced low field mobility, and immunity from radiation induced latch-up. A common belief that semiconductor devices function better at low temperatures is generally true for bulk devices but it does not hold true for deep sub-micron SOI CMOS devices with microscopic device features of 0.25 micrometers and smaller. Various temperature sensitive device parameters and device characteristics have recently been reported in the literature. Behavior of state of the art technology devices under such conditions needs to be evaluated in order to determine possible modifications in the device design for better performance and survivability under extreme environments. Here, we present a unique approach of developing electronics for extreme environments to benefit future NASA missions as described above. This will also benefit other long transit/life time missions such as the solar sail and planetary outposts in which electronics is out open in the unshielded space at the ambient space

  7. Electronic transport in graphene

    NASA Astrophysics Data System (ADS)

    Zhang, Yuanbo

    This dissertation focuses on the electronic transport properties of graphene, a single atomic layer of graphite. Graphene is a novel two-dimensional system in which electron transport is effectively governed by the relativistic quantum theory. We discover a variety of new phenomenon which stem from the "relativistic" nature of the electron dynamics in graphene. An unusual quantum Hall (QH) effect is discovered in graphene at low temperatures and strong magnetic fields. Unlike conventional two-dimensional electron systems, in graphene the observed quantization condition is characterized by half integers rather than integers. Our investigation of the magneto-oscillations in resistance reveals a Berry's phase of pi associated with the electron motion in graphene. The half-integer quantization, as well as the Berry's phase, is attributed to the peculiar topology of the graphene band structure with a linear dispersion relation and vanishing mass near the Dirac point, which can be described by relativistic quantum electrodynamics. This is further confirmed by our measurement of the effective carrier mass, m*, which obeys Einstein's equation: E = m*c*2 where c* ≈ c/300 is the effective speed of light for electrons in graphene. The availability of high magnetic fields up to 45 Tesla allows us to study the magneto-transport in graphene in the extreme quantum limit. Under such condition, we discover new sets of QH states at filling factors nu = 0, +/-1, +/-4, indicating the lifting of the four-fold degeneracy of the previously observed QH states at nu = +/-4(|n|+1/2), where n is the Landau level index. In particular, the presence of the nu = 0, +/-1 QH states indicates that the Landau level at the charge neutral Dirac point splits into four sub-levels, lifting both sublattice and spin degeneracy, thereby potentially indicating a many-body correlation in this LL. The QH effect at nu = +/-4 is investigated in tilted magnetic fields and is attributed to lifting of the n

  8. Methods development for electron transport

    NASA Astrophysics Data System (ADS)

    Ganapol, Barry D.

    1992-04-01

    This report consists of two code manuals and an article recently published in the proceedings of the American Nuclear Society Mathematics and Computation Topical Meeting held in Pittsburgh. In these presentations, deterministic calculational methods simulating electron transport in solids are detailed. The first method presented (Section 2) is for the solution of the Spencer-Lewis equation in which electron motion is characterized by continuous slowing down theory and a pathlength formulation. The FN solution to the standard monoenergetic transport equation for electron transport with isotropic scattering in finite media is given in Section 3. For both codes, complete flow charts, operational instructions and sample problems are included. Finally, in Section 4, an application of the multigroup formulation of electron transport in an infinite medium is used to verify an equivalent SN formulation. For this case, anisotropic scattering is also included.

  9. Regimes of suprathermal electron transport

    SciTech Connect

    Glinsky, M.E.

    1995-07-01

    Regimes of the one-dimensional (1-D) transport of suprathermal electrons into a cold background plasma are delineated. A well ordered temporal progression is found through eras where {ital J}{center_dot}{ital E} heating, hot electron--cold electron collisional heating, and diffusive heat flow dominate the cold electron energy equation. Scaling relations for how important quantities such as the width and temperature of the heated layer of cold electrons evolve with time are presented. These scaling relations are extracted from a simple 1-D model of the transport which can be written in dimensionless form with one free parameter. The parameter is shown to be the suprathermal electron velocity divided by the drift velocity of cold electrons which balances the suprathermal current. Special attention is paid to the assumptions which allow the reduction from the collisional Vlasov equation, using a Fokker--Planck collision operator, to this simple model. These model equations are numerically solved and compared to both the scaling relations and a more complete multigroup electron diffusion transport. Implications of the scaling relations on fast ion generation, magnetic field generation, and electric field inhibition of electron transport are examined as they apply to laser heated plasmas. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  10. Plutonium transport in the environment.

    PubMed

    Kersting, Annie B

    2013-04-01

    The recent estimated global stockpile of separated plutonium (Pu) worldwide is about 500 t, with equal contributions from nuclear weapons and civilian nuclear energy. Independent of the United States' future nuclear energy policy, the current large and increasing stockpile of Pu needs to be safely isolated from the biosphere and stored for thousands of years. Recent laboratory and field studies have demonstrated the ability of colloids (1-1000 nm particles) to facilitate the migration of strongly sorbing contaminants such as Pu. In understanding the dominant processes that may facilitate the transport of Pu, the initial source chemistry and groundwater chemistry are important factors, as no one process can explain all the different field observations of Pu transport. Very little is known about the molecular-scale geochemical and biochemical mechanisms controlling Pu transport, leaving our conceptual model incomplete. Equally uncertain are the conditions that inhibit the cycling and mobility of Pu in the subsurface. Without a better mechanistic understanding for Pu at the molecular level, we cannot advance our ability to model its transport behavior and achieve confidence in predicting long-term transport. Without a conceptual model that can successfully predict long-term Pu behavior and ultimately isolation from the biosphere, the public will remain skeptical that nuclear energy is a viable and an attractive alternative to counter global warming effects of carbon-based energy alternatives. This review summarizes our current understanding of the relevant conditions and processes controlling the behavior of Pu in the environment, gaps in our scientific knowledge, and future research needs. PMID:23458827

  11. Plutonium transport in the environment.

    PubMed

    Kersting, Annie B

    2013-04-01

    The recent estimated global stockpile of separated plutonium (Pu) worldwide is about 500 t, with equal contributions from nuclear weapons and civilian nuclear energy. Independent of the United States' future nuclear energy policy, the current large and increasing stockpile of Pu needs to be safely isolated from the biosphere and stored for thousands of years. Recent laboratory and field studies have demonstrated the ability of colloids (1-1000 nm particles) to facilitate the migration of strongly sorbing contaminants such as Pu. In understanding the dominant processes that may facilitate the transport of Pu, the initial source chemistry and groundwater chemistry are important factors, as no one process can explain all the different field observations of Pu transport. Very little is known about the molecular-scale geochemical and biochemical mechanisms controlling Pu transport, leaving our conceptual model incomplete. Equally uncertain are the conditions that inhibit the cycling and mobility of Pu in the subsurface. Without a better mechanistic understanding for Pu at the molecular level, we cannot advance our ability to model its transport behavior and achieve confidence in predicting long-term transport. Without a conceptual model that can successfully predict long-term Pu behavior and ultimately isolation from the biosphere, the public will remain skeptical that nuclear energy is a viable and an attractive alternative to counter global warming effects of carbon-based energy alternatives. This review summarizes our current understanding of the relevant conditions and processes controlling the behavior of Pu in the environment, gaps in our scientific knowledge, and future research needs.

  12. Electron transport in bipyridinium films.

    PubMed

    Raymo, Françisco M; Alvarado, Robert J

    2004-01-01

    Bipyridinium dications are versatile building blocks for the assembly of functional materials. In particular, their reliable electrochemical response has encouraged the design of electroactive films. Diverse and elegant experimental strategies to coat metallic and semiconducting electrodes with bipyridinium compounds have, in fact, emerged over the past two decades. The resulting interfacial assemblies span from a few nanometers to several micrometers in thickness. They incorporate from a single molecular layer to large collections of entangled polymer chains. They transport electrons efficiently from the electrode surface to the film/solution interface and vice versa. Electron self-exchange between and the physical diffusion of the bipyridinium building blocks conspire in defining the charge transport properties of these fascinating electroactive assemblies. Often, the matrix of electron-deficient bipyridinium dications can be exploited to entrap electron-rich analytes. Electrostatic interactions promote the supramolecular association of the guests with the surface-confined host matrix. Furthermore, chromophoric sites can be coupled to the bipyridinium dications to produce photosensitive arrays capable of harvesting light and generating current. Thus, thorough investigations on the fundamental properties of these functional molecule-based materials can lead to promising applications in electroanalysis and solar energy conversion, while contributing to advances in the basic understanding of electron transport in interfacial assemblies.

  13. Electronic Transport in Carbon Nanomaterials

    SciTech Connect

    Lopez-Benzanilla, Alejandro; Meunier, Vincent; Sumpter, Bobby G; Roche, Stephan; Cruz Silva, Eduardo

    2012-01-01

    Over the past decade, transport measurements on individual single-wall nanotubes have played a prominent role in developing our understanding of this novel carbon conductor. These measurements have identified both metallic and semiconducting nanotubes, determined their dominant electronic scattering mechanisms, and elucidated in great detail the properties of their quantized energy spectrum. Recent technological breakthroughs in nanotube device fabrication and electronic measurement have made possible experiments of unprecedented precision that reveal new and surprising phenomena. In this review, we present the fundamental properties of nanotubes side by side with the newest discoveries and also discuss some of the most exciting emerging directions.

  14. Mesoscopic electronics beyond DC transport

    NASA Astrophysics Data System (ADS)

    di Carlo, Leonardo

    Since the inception of mesoscopic electronics in the 1980's, direct current (dc) measurements have underpinned experiments in quantum transport. Novel techniques complementing dc transport are becoming paramount to new developments in mesoscopic electronics, particularly as the road is paved toward quantum information processing. This thesis describes seven experiments on GaAs/AlGaAs and graphene nanostructures unified by experimental techniques going beyond traditional dc transport. Firstly, dc current induced by microwave radiation applied to an open chaotic quantum dot is investigated. Asymmetry of mesoscopic fluctuations of induced current in perpendicular magnetic field is established as a tool for separating the quantum photovoltaic effect from classical rectification. A differential charge sensing technique is next developed using integrated quantum point contacts to resolve the spatial distribution of charge inside a double quantum clot. An accurate method for determining interdot tunnel coupling and electron temperature using charge sensing is demonstrated. A two-channel system for detecting current noise in mesoscopic conductors is developed, enabling four experiments where shot noise probes transmission properties not available in dc transport and Johnson noise serves as an electron thermometer. Suppressed shot noise is observed in quantum point contacts at zero parallel magnetic field, associated with the 0.7 structure in conductance. This suppression evolves with increasing field into the shot-noise signature of spin-lifted mode degeneracy. Quantitative agreement is found with a phenomenological model for density-dependent mode splitting. Shot noise measurements of multi-lead quantum-dot structures in the Coulomb blockade regime distill the mechanisms by which Coulomb interaction and quantum indistinguishability correlate electron flow. Gate-controlled sign reversal of noise cross correlation in two capacitively-coupled dots is observed, and shown to

  15. Electron Transport in Hall Thrusters

    NASA Astrophysics Data System (ADS)

    McDonald, Michael Sean

    Despite high technological maturity and a long flight heritage, computer models of Hall thrusters remain dependent on empirical inputs and a large part of thruster development to date has been heavily experimental in nature. This empirical approach will become increasingly unsustainable as new high-power thrusters tax existing ground test facilities and more exotic thruster designs stretch and strain the boundaries of existing design experience. The fundamental obstacle preventing predictive modeling of Hall thruster plasma properties and channel erosion is the lack of a first-principles description of electron transport across the strong magnetic fields between the cathode and anode. In spite of an abundance of proposed transport mechanisms, accurate assessments of the magnitude of electron current due to any one mechanism are scarce, and comparative studies of their relative influence on a single thruster platform simply do not exist. Lacking a clear idea of what mechanism(s) are primarily responsible for transport, it is understandably difficult for the electric propulsion scientist to focus his or her theoretical and computational tools on the right targets. This work presents a primarily experimental investigation of collisional and turbulent Hall thruster electron transport mechanisms. High-speed imaging of the thruster discharge channel at tens of thousands of frames per second reveals omnipresent rotating regions of elevated light emission, identified with a rotating spoke instability. This turbulent instability has been shown through construction of an azimuthally segmented anode to drive significant cross-field electron current in the discharge channel, and suggestive evidence points to its spatial extent into the thruster near-field plume as well. Electron trajectory simulations in experimentally measured thruster electromagnetic fields indicate that binary collisional transport mechanisms are not significant in the thruster plume, and experiments

  16. Electron transport in granular metals.

    PubMed

    Altland, Alexander; Glazman, Leonid I; Kamenev, Alex

    2004-01-16

    We consider thermodynamic and transport properties of a long granular array with strongly connected grains (intergrain conductance g>1). We find that the system's conductance and differential capacitance exhibits activated behavior, approximately exp([-T(*)/T]. The gap T(*) represents the energy needed to create a long single-electron charge soliton propagating through the array. This scale is parametrically larger than the energy at which conventional perturbation theory breaks down.

  17. Electronic transport in unconventional superconductors

    SciTech Connect

    Graf, M.J.

    1998-12-31

    The author investigates the electron transport coefficients in unconventional superconductors at low temperatures, where charge and heat transport are dominated by electron scattering from random lattice defects. He discusses the features of the pairing symmetry, Fermi surface, and excitation spectrum which are reflected in the low temperature heat transport. For temperatures {kappa}{sub B}T {approx_lt} {gamma} {much_lt} {Delta}{sub 0}, where {gamma} is the bandwidth of impurity induced Andreev states, certain eigenvalues become universal, i.e., independent of the impurity concentration and phase shift. Deep in the superconducting phase ({kappa}{sub B}T {approx_lt} {gamma}) the Wiedemann-Franz law, with Sommerfeld`s value of the Lorenz number, is recovered. He compares the results for theoretical models of unconventional superconductivity in high-{Tc} and heavy fermion superconductors with experiment. The findings show that impurities are a sensitive probe of the low-energy excitation spectrum, and that the zero-temperature limit of the transport coefficients provides an important test of the order parameter symmetry.

  18. Harsh environments electronics : downhole applications.

    SciTech Connect

    Vianco, Paul Thomas

    2011-03-01

    The development and operational sustainment of renewable (geothermal) and non-renewable (fossil fuel) energy resources will be accompanied by increasingly higher costs factors: exploration and site preparation, operational maintenance and repair. Increased government oversight in the wake of the Gulf oil spill will only add to the cost burden. It is important to understand that downhole conditions are not just about elevated temperatures. It is often construed that military electronics are exposed to the upper limit in terms of extreme service environments. Probably the harshest of all service conditions for electronics and electrical equipment are those in oil, gas, and geothermal wells. From the technology perspective, advanced materials, sensors, and microelectronics devices are benefificial to the exploration and sustainment of energy resources, especially in terms of lower costs. Besides the need for the science that creates these breakthroughs - there is also a need for sustained engineering development and testing. Downhole oil, gas, and geothermal well applications can have a wide range of environments and reliability requirements: Temperature, Pressure, Vibration, Corrosion, and Service duration. All too frequently, these conditions are not well-defifined because the application is labeled as 'high temperature'. This ambiguity is problematic when the investigation turns to new approaches for electronic packaging solutions. The objective is to develop harsh environment, electronic packaging that meets customer requirements of cost, performance, and reliability. There are a number of challenges: (1) Materials sets - solder alloys, substrate materials; (2) Manufacturing process - low to middle volumes, low defect counts, new equipment technologies; and (3) Reliability testing - requirements documents, test methods and modeling, relevant standards documents. The cost to develop and sustain renewable and non-renewable energy resources will continue to escalate

  19. Mars Transportation Environment Definition Document

    NASA Technical Reports Server (NTRS)

    Alexander, M. (Editor)

    2001-01-01

    This document provides a compilation of environments knowledge about the planet Mars. Information is divided into three catagories: (1) interplanetary space environments (environments required by the technical community to travel to and from Mars); (2) atmospheric environments (environments needed to aerocapture, aerobrake, or use aeroassist for precision trajectories down to the surface); and (3) surface environments (environments needed to have robots or explorers survive and work on the surface).

  20. Regulation of Photosynthetic Electron Transport and Photoinhibition

    PubMed Central

    Roach, Thomas; Krieger-Liszkay, Anja Krieger

    2014-01-01

    Photosynthetic organisms and isolated photosystems are of interest for technical applications. In nature, photosynthetic electron transport has to work efficiently in contrasting environments such as shade and full sunlight at noon. Photosynthetic electron transport is regulated on many levels, starting with the energy transfer processes in antenna and ending with how reducing power is ultimately partitioned. This review starts by explaining how light energy can be dissipated or distributed by the various mechanisms of non-photochemical quenching, including thermal dissipation and state transitions, and how these processes influence photoinhibition of photosystem II (PSII). Furthermore, we will highlight the importance of the various alternative electron transport pathways, including the use of oxygen as the terminal electron acceptor and cyclic flow around photosystem I (PSI), the latter which seem particularly relevant to preventing photoinhibition of photosystem I. The control of excitation pressure in combination with the partitioning of reducing power influences the light-dependent formation of reactive oxygen species in PSII and in PSI, which may be a very important consideration to any artificial photosynthetic system or technical device using photosynthetic organisms. PMID:24678670

  1. Inner Radiation Belt Representation of the Energetic Electron Environment: Model and Data Synthesis Using the Salammbo Radiation Belt Transport Code and Los Alamos Geosynchronous and GPS Energetic Particle Data

    NASA Technical Reports Server (NTRS)

    Friedel, R. H. W.; Bourdarie, S.; Fennell, J.; Kanekal, S.; Cayton, T. E.

    2004-01-01

    The highly energetic electron environment in the inner magnetosphere (GEO inward) has received a lot of research attention in resent years, as the dynamics of relativistic electron acceleration and transport are not yet fully understood. These electrons can cause deep dielectric charging in any space hardware in the MEO to GEO region. We use a new and novel approach to obtain a global representation of the inner magnetospheric energetic electron environment, which can reproduce the absolute environment (flux) for any spacecraft orbit in that region to within a factor of 2 for the energy range of 100 KeV to 5 MeV electrons, for any levels of magnetospheric activity. We combine the extensive set of inner magnetospheric energetic electron observations available at Los Alamos with the physics based Salammbo transport code, using the data assimilation technique of "nudging". This in effect input in-situ data into the code and allows the diffusion mechanisms in the code to interpolate the data into regions and times of no data availability. We present here details of the methods used, both in the data assimilation process and in the necessary inter-calibration of the input data used. We will present sample runs of the model/data code and compare the results to test spacecraft data not used in the data assimilation process.

  2. Environic implications of lighter than air transportation

    NASA Technical Reports Server (NTRS)

    Horsbrugh, P.

    1975-01-01

    The advent of any new system of transportation must now be reviewed in the physical context and texture of the landscape. Henceforward, all transportation systems will be considered in respect of their effects upon the environment to ensure that they afford an environic asset as well as provide an economic benefit. The obligations which now confront the buoyancy engineers are emphasized so that they may respond to these ethical and environic urgencies simultaneously with routine technical development.

  3. Electron Transport in Short Peptide Single Molecules

    NASA Astrophysics Data System (ADS)

    Cui, Jing; Brisendine, Joseph; Ng, Fay; Nuckolls, Colin; Koder, Ronald; Venkarataman, Latha

    We present a study of the electron transport through a series of short peptides using scanning tunneling microscope-based break junction method. Our work is motivated by the need to gain a better understanding of how various levels of protein structure contribute to the remarkable capacity of proteins to transport charge in biophysical processes such as respiration and photosynthesis. We focus here on short mono, di and tri-peptides, and probe their conductance when bound to gold electrodes in a native buffer environment. We first show that these peptides can bind to gold through amine, carboxyl, thiol and methyl-sulfide termini. We then focus on two systems (glycine and alanine) and show that their conductance decays faster than alkanes terminated by the same linkers. Importantly, our results show that the peptide bond is less conductive than a sigma carbon-carbon bond. This work was supported in part by NSF-DMR 1507440.

  4. Vapor Transport to Indoor Environments

    EPA Science Inventory

    The indoor environment is an important microenvironment for human exposure to chemicals, both because people spend most of their time indoors and because chemicals are often at higher concentrations indoors versus outdoors. This chapter reviews the major components in estimating ...

  5. 3D cryo-electron reconstruction of BmrA, a bacterial multidrug ABC transporter in an inward-facing conformation and in a lipidic environment.

    PubMed

    Fribourg, Pierre Frederic; Chami, Mohamed; Sorzano, Carlos Oscar S; Gubellini, Francesca; Marabini, Roberto; Marco, Sergio; Jault, Jean-Michel; Lévy, Daniel

    2014-05-15

    ABC (ATP-binding cassette) membrane exporters are efflux transporters of a wide diversity of molecule across the membrane at the expense of ATP. A key issue regarding their catalytic cycle is whether or not their nucleotide-binding domains (NBDs) are physically disengaged in the resting state. To settle this controversy, we obtained structural data on BmrA, a bacterial multidrug homodimeric ABC transporter, in a membrane-embedded state. BmrA in the apostate was reconstituted in lipid bilayers forming a mixture of ring-shaped structures of 24 or 39 homodimers. Three-dimensional models of the ring-shaped structures of 24 or 39 homodimers were calculated at 2.3 nm and 2.5 nm resolution from cryo-electron microscopy, respectively. In these structures, BmrA adopts an inward-facing open conformation similar to that found in mouse P-glycoprotein structure with the NBDs separated by 3 nm. Both lipidic leaflets delimiting the transmembrane domains of BmrA were clearly resolved. In planar membrane sheets, the NBDs were even more separated. BmrA in an ATP-bound conformation was determined from two-dimensional crystals grown in the presence of ATP and vanadate. A projection map calculated at 1.6 nm resolution shows an open outward-facing conformation. Overall, the data are consistent with a mechanism of drug transport involving large conformational changes of BmrA and show that a bacterial ABC exporter can adopt at least two open inward conformations in lipid membrane.

  6. Coupled electron-photon radiation transport

    SciTech Connect

    Lorence, L.; Kensek, R.P.; Valdez, G.D.; Drumm, C.R.; Fan, W.C.; Powell, J.L.

    2000-01-17

    Massively-parallel computers allow detailed 3D radiation transport simulations to be performed to analyze the response of complex systems to radiation. This has been recently been demonstrated with the coupled electron-photon Monte Carlo code, ITS. To enable such calculations, the combinatorial geometry capability of ITS was improved. For greater geometrical flexibility, a version of ITS is under development that can track particles in CAD geometries. Deterministic radiation transport codes that utilize an unstructured spatial mesh are also being devised. For electron transport, the authors are investigating second-order forms of the transport equations which, when discretized, yield symmetric positive definite matrices. A novel parallelization strategy, simultaneously solving for spatial and angular unknowns, has been applied to the even- and odd-parity forms of the transport equation on a 2D unstructured spatial mesh. Another second-order form, the self-adjoint angular flux transport equation, also shows promise for electron transport.

  7. Numerical Solution of 3D Poisson-Nernst-Planck Equations Coupled with Classical Density Functional Theory for Modeling Ion and Electron Transport in a Confined Environment

    SciTech Connect

    Meng, Da; Zheng, Bin; Lin, Guang; Sushko, Maria L.

    2014-08-29

    We have developed efficient numerical algorithms for the solution of 3D steady-state Poisson-Nernst-Planck equations (PNP) with excess chemical potentials described by the classical density functional theory (cDFT). The coupled PNP equations are discretized by finite difference scheme and solved iteratively by Gummel method with relaxation. The Nernst-Planck equations are transformed into Laplace equations through the Slotboom transformation. Algebraic multigrid method is then applied to efficiently solve the Poisson equation and the transformed Nernst-Planck equations. A novel strategy for calculating excess chemical potentials through fast Fourier transforms is proposed which reduces computational complexity from O(N2) to O(NlogN) where N is the number of grid points. Integrals involving Dirac delta function are evaluated directly by coordinate transformation which yields more accurate result compared to applying numerical quadrature to an approximated delta function. Numerical results for ion and electron transport in solid electrolyte for Li ion batteries are shown to be in good agreement with the experimental data and the results from previous studies.

  8. Multidimensional electron-photon transport with standard discrete ordinates codes

    SciTech Connect

    Drumm, C.R.

    1995-12-31

    A method is described for generating electron cross sections that are compatible with standard discrete ordinates codes without modification. There are many advantages of using an established discrete ordinates solver, e.g. immediately available adjoint capability. Coupled electron-photon transport capability is needed for many applications, including the modeling of the response of electronics components to space and man-made radiation environments. The cross sections have been successfully used in the DORT, TWODANT and TORT discrete ordinates codes. The cross sections are shown to provide accurate and efficient solutions to certain multidimensional electronphoton transport problems.

  9. Transport experiments with Dirac electrons

    NASA Astrophysics Data System (ADS)

    Checkelsky, Joseph George

    This thesis presents transport experiments performed on solid state systems in which the behavior of the charge carriers can be described by the Dirac equation. Unlike the massive carriers in a typical material, in these systems the carriers behave like massless fermions with a photon-like dispersion predicted to greatly modify their spin and charge transport properties. The first system studied is graphene, a crystalline monolayer of carbon arranged in a hexagonal lattice. The band structure calculated from the hexagonal lattice has the form of the massless Dirac Hamiltonian. At the charge neutral Dirac point, we find that application of a magnetic field drives a transition to an insulating state. We also study the thermoelectric properties of graphene and find that the states near the Dirac point have a unique response compared to those at higher charge density. The second system is the 3D topological insulator Bi2Se3, where a Dirac-like dispersion for states on the 2D surface of the insulating 3D crystal arises as a result of the topology of the 3D bands and time reversal symmetry. To access the transport properties of the 2D states, we suppress the remnant bulk conduction channel by chemical doping and electrostatic gating. In bulk crystals we find strong quantum corrections to transport at low temperature when the bulk conduction channel is maximally suppressed. In microscopic crystals we are able better to isolate the surface conduction channel properties. We identify in-gap conducting states that have relatively high mobility compared to the bulk and exhibit weak anti-localization, consistent with predictions for protected 2D surface states with strong spin-orbit coupling.

  10. The Electron Transport Chain: An Interactive Simulation

    ERIC Educational Resources Information Center

    Romero, Chris; Choun, James

    2014-01-01

    This activity provides students an interactive demonstration of the electron transport chain and chemiosmosis during aerobic respiration. Students use simple, everyday objects as hydrogen ions and electrons and play the roles of the various proteins embedded in the inner mitochondrial membrane to show how this specific process in cellular…

  11. Study of Electron Transport and Amplification in Diamond

    SciTech Connect

    Ben-Zvi, Ilan; Muller, Erik

    2015-01-05

    The development of the Diamond Amplified Photocathode (DAP) has produced significant results under our previous HEP funded efforts both on the fabrication of working devices and the understanding of the underlying physics governing its performance. The results presented here substantiate the use of diamond as both a secondary electron amplifier for high-brightness, high-average-current electron sources and as a photon and particle detector in harsh radiation environments. Very high average current densities (>10A/cm2) have been transported through diamond material. The transport has been measured as a function of incident photon energy and found to be in good agreement with theoretical models. Measurements of the charge transport for photon energies near the carbon K-edge (290 eV for sp3 bonded carbon) have provided insight into carrier loss due to diffusion; modeling of this aspect of charge transport is underway. The response of diamond to nanosecond x-ray pulses has been measured; in this regime the charge transport is as expected. Electron emission from hydrogenated diamond has been measured using both electron and x-ray generated carriers; a gain of 178 has been observed for electron-generated carriers. The energy spectrum of the emitted electrons has been measured, providing insight into the electron affinity and ultimately the thermal emittance. The origin of charge trapping in diamond has been investigated for both bulk and surface trapping

  12. Monte Carlo electron/photon transport

    SciTech Connect

    Mack, J.M.; Morel, J.E.; Hughes, H.G.

    1985-01-01

    A review of nonplasma coupled electron/photon transport using Monte Carlo method is presented. Remarks are mainly restricted to linerarized formalisms at electron energies from 1 keV to 1000 MeV. Applications involving pulse-height estimation, transport in external magnetic fields, and optical Cerenkov production are discussed to underscore the importance of this branch of computational physics. Advances in electron multigroup cross-section generation is reported, and its impact on future code development assessed. Progress toward the transformation of MCNP into a generalized neutral/charged-particle Monte Carlo code is described. 48 refs.

  13. Electron transport through single carbon nanotubes

    SciTech Connect

    Schenkel, Thomas; Chai, G.; Heinrich, H.; Chow, L.; Schenkel, T.

    2007-08-01

    We report on the transport of energetic electrons through single, well aligned multi-wall carbon nanotubes (CNT). Embedding of CNTs in a protective carbon fiber coating enables the application of focused ion beam based sample preparation techniques for the non-destructive isolation and alignment of individual tubes. Aligned tubes with lengths of 0.7 to 3 mu m allow transport of 300 keV electrons in a transmission electron microscope through their hollow cores at zero degree incident angles and for a misalignment of up to 1 degree.

  14. Electronic structure calculations in arbitrary electrostatic environments

    NASA Astrophysics Data System (ADS)

    Watson, Mark A.; Rappoport, Dmitrij; Lee, Elizabeth M. Y.; Olivares-Amaya, Roberto; Aspuru-Guzik, Alán

    2012-01-01

    Modeling of electronic structure of molecules in electrostatic environments is of considerable relevance for surface-enhanced spectroscopy and molecular electronics. We have developed and implemented a novel approach to the molecular electronic structure in arbitrary electrostatic environments that is compatible with standard quantum chemical methods and can be applied to medium-sized and large molecules. The scheme denoted CheESE (chemistry in electrostatic environments) is based on the description of molecular electronic structure subject to a boundary condition on the system/environment interface. Thus, it is particularly suited to study molecules on metallic surfaces. The proposed model is capable of describing both electrostatic effects near nanostructured metallic surfaces and image-charge effects. We present an implementation of the CheESE model as a library module and show example applications to neutral and negatively charged molecules.

  15. Electronic Transport in Organic Molecules

    NASA Astrophysics Data System (ADS)

    Tian, W.; Samanta, M. P.; Henderson, J. I.; Kubiak, C. P.; Datta, S.

    1996-03-01

    A systematic theoretical study of the conductance of a class of organic molecules connected between two gold cantact pads will be presented. This class of molecules consists of oligomers of benzene rings linked at their para-positions and terminated with suitable ligand end groups designed to bond to gold substrates. Such molecules are currently being investigated experimentally for use as interconnectors in nanoscale electronic devices (J.Guay et al, J.Am.Chem.Soc., 115,1869, (1993); M.Dorogi et al, Phys. Rev. B52,9071,(1995); D.B.Janes et al, Superlatt. and Microstruc., in press). Analytical and numerical results will be presented illustrating effects of Metal Induced Gap States (MIGS), end group atoms, geometric and molecular structure on the measured conductance.

  16. Radiation Hardened Electronics for Space Environments (RHESE)

    NASA Technical Reports Server (NTRS)

    Keys, Andrew S.; Adams, James H.; Frazier, Donald O.; Patrick, Marshall C.; Watson, Michael D.; Johnson, Michael A.; Cressler, John D.; Kolawa, Elizabeth A.

    2007-01-01

    Radiation Environmental Modeling is crucial to proper predictive modeling and electronic response to the radiation environment. When compared to on-orbit data, CREME96 has been shown to be inaccurate in predicting the radiation environment. The NEDD bases much of its radiation environment data on CREME96 output. Close coordination and partnership with DoD radiation-hardened efforts will result in leveraged - not duplicated or independently developed - technology capabilities of: a) Radiation-hardened, reconfigurable FPGA-based electronics; and b) High Performance Processors (NOT duplication or independent development).

  17. Resistive Plate Chambers: electron transport and modeling

    NASA Astrophysics Data System (ADS)

    Bošnjaković, D.; Petrović, Z. Lj; Dujko, S.

    2014-12-01

    We study the electron transport in gas mixtures used by Resistive Plate Chambers (RPCs) in high energy physics experiments at CERN. Calculations are performed using a multi term theory for solving the Boltzmann equation. We identify the effects induced by non-conservative nature of electron attachment, including attachment heating of electrons and negative differential conductivity (NDC). NDC was observed only in the bulk component of drift velocity. Using our Monte Carlo technique, we calculate the spatially resolved transport properties in order to investigate the origin of these effects. We also present our microscopic approach to modeling of RPCs which is based on Monte Carlo method. Calculated results for a timing RPC show good agreement with an analytical model and experimental data. Different cross section sets for electron scattering in C2H2F4 are used for comparison and analysis.

  18. Electronic transport in polycrystalline samples of icosahedral phases

    NASA Astrophysics Data System (ADS)

    Vekilov, Yu. Kh.; Chernikov, M. A.; Dolinichek, Ya.

    2016-01-01

    The low-temperature electronic transport in polycrystals of quasicrystalline phases with an icosahedral structure has been analyzed within the model of the granular electronic system. In this model, the grains (drops) of a metallic icosahedral phase are surrounded by extended defects and grain boundaries, which create an insulating environment. The electron transport in this model is determined by the size quantization of electronic states inside metallic grains, by intergranular tunneling, and by electrostatic barriers. Depending on the temperature and structural state of the system, the hopping conductivity with variable lengths of jumps in the Efros-Shklovskii or Mott regime is observed with predominantly elastic cotunneling. In the case of strong intergranular coupling, the system passes into the metallic regime with the exponential temperature dependence of the electrical conductivity.

  19. Electron environment specification models for Galileo

    NASA Astrophysics Data System (ADS)

    Lazaro, Didier; Bourdarie, Sebastien; Hands, Alex; Ryden, Keith; Nieminen, Petteri

    The MEO radiation hazard is becoming an increasingly important consideration with an ever rising number of satellites missions spending most of their time in this environment. This region lies in the heart of the highly dynamic electron radiation belt, where very large radiation doses can be encountered unless proper shielding to critical systems and components is applied. Significant internal charging hazards also arise in the MEO regime. For electron environment specification at Galileo altitude, new models have been developed and implemented: long term effects model for dose evaluation, statistical model for internal charging analysis and latitudinal model for ELDRS analysis. Models outputs, tools and validation with observations (Giove-A data) and existing models (such as FLUMIC) are presented . "Energetic Electron Environment Models for MEO" Co 21403/08/NL/JD in consortium with ONERA, QinetiQ, SSTL and CNES .

  20. Electronic materials processing and the microgravity environment

    NASA Technical Reports Server (NTRS)

    Witt, A. F.

    1988-01-01

    The nature and origin of deficiencies in bulk electronic materials for device fabrication are analyzed. It is found that gravity generated perturbations during their formation account largely for the introduction of critical chemical and crystalline defects and, moreover, are responsible for the still existing gap between theory and experiment and thus for excessive reliance on proprietary empiricism in processing technology. Exploration of the potential of reduced gravity environment for electronic materials processing is found to be not only desirable but mandatory.

  1. Numerical solution of the electron transport equation

    NASA Astrophysics Data System (ADS)

    Woods, Mark

    The electron transport equation has been solved many times for a variety of reasons. The main difficulty in its numerical solution is that it is a very stiff boundary value problem. The most common numerical methods for solving boundary value problems are symmetric collocation methods and shooting methods. Both of these types of methods can only be applied to the electron transport equation if the boundary conditions are altered with unrealistic assumptions because they require too many points to be practical. Further, they result in oscillating and negative solutions, which are physically meaningless for the problem at hand. For these reasons, all numerical methods for this problem to date are a bit unusual because they were designed to try and avoid the problem of extreme stiffness. This dissertation shows that there is no need to introduce spurious boundary conditions or invent other numerical methods for the electron transport equation. Rather, there already exists methods for very stiff boundary value problems within the numerical analysis literature. We demonstrate one such method in which the fast and slow modes of the boundary value problem are essentially decoupled. This allows for an upwind finite difference method to be applied to each mode as is appropriate. This greatly reduces the number of points needed in the mesh, and we demonstrate how this eliminates the need to define new boundary conditions. This method is verified by showing that under certain restrictive assumptions, the electron transport equation has an exact solution that can be written as an integral. We show that the solution from the upwind method agrees with the quadrature evaluation of the exact solution. This serves to verify that the upwind method is properly solving the electron transport equation. Further, it is demonstrated that the output of the upwind method can be used to compute auroral light emissions.

  2. Electron Transport Through Single Fullerene Molecules (abstract)

    NASA Astrophysics Data System (ADS)

    Stróżecka, Anna; Muthukumar, Kaliappan; Larsson, J. Andreas; Voigtländer, Bert

    2009-04-01

    Fullerenes show potential for applications in nanotechnology due to the possibility of tuning their properties by doping or functionalization. In particular, the endohedral doping of the hollow carbon cage with metal atoms allows changing the electronic and magnetic properties of the molecule without distorting the geometry of the outer shell. Here we present a low temperature scanning tunneling microscopy (STM) and spectroscopy study of the vibrational and transport properties of Ce2atC80 metallofullerenes. We observe that electron transport through the endohedral fullerene is strongly mediated by excitation of molecular vibrations, especially the dynamics of encapsulated atoms. We measure the conductance of the single-molecule junction upon contact between the molecule and the STM tip. To determine the role of doping atoms we compare the results obtained for the endohedrally doped species with those for a hollow fullerene. Analysis shows that localization of electron density on encapsulated atoms hinders the conduction process through the fullerene.

  3. The effect of electron-electron interaction induced dephasing on electronic transport in graphene nanoribbons

    SciTech Connect

    Kahnoj, Sina Soleimani; Touski, Shoeib Babaee; Pourfath, Mahdi E-mail: pourfath@iue.tuwien.ac.at

    2014-09-08

    The effect of dephasing induced by electron-electron interaction on electronic transport in graphene nanoribbons is theoretically investigated. In the presence of disorder in graphene nanoribbons, wavefunction of electrons can set up standing waves along the channel and the conductance exponentially decreases with the ribbon's length. Employing the non-equilibrium Green's function formalism along with an accurate model for describing the dephasing induced by electron-electron interaction, we show that this kind of interaction prevents localization and transport of electrons remains in the diffusive regime where the conductance is inversely proportional to the ribbon's length.

  4. Electron ripple injection concept for transport control

    SciTech Connect

    Choe, W.; Ono, M.; Hwang, Y.S.

    1992-01-01

    Recent experiments in many devices have provided firm evidence that the edge radial electric field profile differs between L- and H-modes, and that these fields can greatly modify transport in tokamak plasmas. A nonintrusive method for inducing radial electric field based on electron ripple injection is being developed by the CDX-U group. This technique utilizes a pair of special coils to create a local magnetic field ripple to trap the electrons at the edge of the plasma. The trapped electrons then drift into the plasma due to the [del]B drift. An ECH power is applied to accelerate electrons to sufficient perpendicular energy to penetrate into the plasma. Application of ECH power to the trapped electrons should provide the desired 20 A of electron current with electrons of a few keV of energy and v[perpendicular]/v[parallel] [much gt] 1. A controlled experiment to investigate the physics of ECH aided ripple injection has been designed on CDX-U. With the set of ripple coils designed for CDX-U, a ripple fraction of [delta] ([double bond] [del]B/B[sub av]) [approximately] 5% is attainable. At this ripple fraction, electrons are trapped if v[perpendicular]/v[parallel] [much gt] 1> (2[delta])[sup [minus][1/2

  5. Self-consistent electron transport in tokamaks

    SciTech Connect

    Gatto, R.; Chavdarovski, I.

    2007-09-15

    Electron particle, momentum, and energy fluxes in axisymmetric toroidal devices are derived from a version of the action-angle collision operator that includes both diffusion and drag in action-space [D. A. Hitchcock, R. D. Hazeltine, and S. M. Mahajan, Phys. Fluids 26, 2603 (1983); H. E. Mynick, J. Plasma Phys. 39, 303 (1988)]. A general result of the theory is that any contribution to transport originating directly from the toroidal frequency of the particle motion is constrained to be zero when the electron temperature is equal to the ion temperature. In particular, this constraint applies to those components of the particle and energy fluxes that are proportional to the magnetic shear, independent of the underlying turbulence and of whether the particles are trapped or untrapped. All the total fluxes describing collisionless transport of passing electrons in steady-state magnetic turbulence contain contributions proportional to the conventional thermodynamic drives, which are always outward, and contributions proportional to the magnetic shear, which have both magnitude and sign dependent on the ion-electron temperature ratio. The turbulent generalization of Ohm's law includes a hyper-resistive term, which flattens the current density profile on a fast time scale, and a turbulent electric field, which can have both signs depending on the electron-ion temperature ratio.

  6. Single-molecule junctions beyond electronic transport.

    PubMed

    Aradhya, Sriharsha V; Venkataraman, Latha

    2013-06-01

    The idea of using individual molecules as active electronic components provided the impetus to develop a variety of experimental platforms to probe their electronic transport properties. Among these, single-molecule junctions in a metal-molecule-metal motif have contributed significantly to our fundamental understanding of the principles required to realize molecular-scale electronic components from resistive wires to reversible switches. The success of these techniques and the growing interest of other disciplines in single-molecule-level characterization are prompting new approaches to investigate metal-molecule-metal junctions with multiple probes. Going beyond electronic transport characterization, these new studies are highlighting both the fundamental and applied aspects of mechanical, optical and thermoelectric properties at the atomic and molecular scales. Furthermore, experimental demonstrations of quantum interference and manipulation of electronic and nuclear spins in single-molecule circuits are heralding new device concepts with no classical analogues. In this Review, we present the emerging methods being used to interrogate multiple properties in single molecule-based devices, detail how these measurements have advanced our understanding of the structure-function relationships in molecular junctions, and discuss the potential for future research and applications.

  7. Extracellular Electron Transport (EET): Metal Cycling in Extreme Places

    NASA Astrophysics Data System (ADS)

    Nealson, K. H.

    2014-12-01

    Extracellular electron transport, or EET, is the process whereby bacteria either donate electrons to an electron acceptor (usually insoluble), or take up electrons from and electron donor (usually insoluble) that is located outside the cell. Iron cycling is inherently linked to EET, as both reduced iron (electron donors), and oxidized iron (electron acceptors) can be found as insoluble minerals, and require specialized molecular machines to accomplish these extracellular geobiological reactions. Bacteria in the group Shewanella are able to catalyze EET in both directions, and are involved with a number of different iron conversions, but are not good role models for extreme conditions - to our knowledge there are no shewanellae that are tolerant to extremes of temperature or pH, the two usual. This being said, when cells are energy starved via limitation for electron acceptors, they respond by turning on the system(s) for EET. Thus, in this presentation the known mechanism(s) of EET will be discussed, along with recent findings and reports of EET-capable organisms from a variety of extreme environments. From these data, I put forward the hypothesis that there are many microbes (many of them from extreme environments) that will be resistant to cultivation by "standard microbiological methods", yet lend themselves well to cultivation via electrochemical methods.

  8. Electronic transport in smectic liquid crystals

    NASA Astrophysics Data System (ADS)

    Shiyanovskaya, I.; Singer, K. D.; Twieg, R. J.; Sukhomlinova, L.; Gettwert, V.

    2002-04-01

    Time-of-flight measurements of transient photoconductivity have revealed bipolar electronic transport in phenylnaphthalene and biphenyl liquid crystals (LC), which exhibit several smectic mesophases. In the phenylnaphthalene LC, the hole mobility is significantly higher than the electron mobility and exhibits different temperature and phase behavior. Electron mobility in the range ~10-5 cm2/V s is temperature activated and remains continuous at the phase transitions. However, hole mobility is nearly temperature independent within the smectic phases, but is very sensitive to smectic order, 10-3 cm2/V s in the smectic-B (Sm-B) and 10-4 cm2/V s in the smectic-A (Sm-A) mesophases. The different behavior for holes and electron transport is due to differing transport mechanisms. The electron mobility is apparently controlled by rate-limiting multiple shallow trapping by impurities, but hole mobility is not. To explain the lack of temperature dependence for hole mobility within the smectic phases we consider two possible polaron transport mechanisms. The first mechanism is based on the hopping of Holstein small polarons in the nonadiabatic limit. The polaron binding energy and transfer integral values, obtained from the model fit, turned out to be sensitive to the molecular order in smectic mesophases. A second possible scenario for temperature-independent hole mobility involves the competion between two different polaron mechanisms involving so-called nearly small molecular polarons and small lattice polarons. Although the extracted transfer integrals and binding energies are reasonable and consistent with the model assumptions, the limited temperature range of the various phases makes it difficult to distinguish between any of the models. In the biphenyl LCs both electron and hole mobilities exhibit temperature activated behavior in the range of 10-5 cm2/V s without sensitivity to the molecular order. The dominating transport mechanism is considered as multiple trapping

  9. Electronic transport in methylated fragments of DNA

    SciTech Connect

    Almeida, M. L. de; Oliveira, J. I. N.; Lima Neto, J. X.; Gomes, C. E. M.; Fulco, U. L. Albuquerque, E. L.; Freire, V. N.; Caetano, E. W. S.; Moura, F. A. B. F. de; Lyra, M. L.

    2015-11-16

    We investigate the electronic transport properties of methylated deoxyribonucleic-acid (DNA) strands, a biological system in which methyl groups are added to DNA (a major epigenetic modification in gene expression), sandwiched between two metallic platinum electrodes. Our theoretical simulations apply an effective Hamiltonian based on a tight-binding model to obtain current-voltage curves related to the non-methylated/methylated DNA strands. The results suggest potential applications in the development of novel biosensors for molecular diagnostics.

  10. Electronic transport in methylated fragments of DNA

    NASA Astrophysics Data System (ADS)

    de Almeida, M. L.; Oliveira, J. I. N.; Lima Neto, J. X.; Gomes, C. E. M.; Fulco, U. L.; Albuquerque, E. L.; Freire, V. N.; Caetano, E. W. S.; de Moura, F. A. B. F.; Lyra, M. L.

    2015-11-01

    We investigate the electronic transport properties of methylated deoxyribonucleic-acid (DNA) strands, a biological system in which methyl groups are added to DNA (a major epigenetic modification in gene expression), sandwiched between two metallic platinum electrodes. Our theoretical simulations apply an effective Hamiltonian based on a tight-binding model to obtain current-voltage curves related to the non-methylated/methylated DNA strands. The results suggest potential applications in the development of novel biosensors for molecular diagnostics.

  11. Electron transport fluxes in potato plateau regime

    SciTech Connect

    Shaing, K.C.; Hazeltine, R.D.

    1997-12-01

    Electron transport fluxes in the potato plateau regime are calculated from the solutions of the drift kinetic equation and fluid equations. It is found that the bootstrap current density remains finite in the region close to the magnetic axis, although it decreases with increasing collision frequency. This finite amount of the bootstrap current in the relatively collisional regime is important in modeling tokamak startup with 100{percent} bootstrap current. {copyright} {ital 1997 American Institute of Physics.}

  12. Electron ripple injection concept for transport control

    SciTech Connect

    Choe, W.; Ono, M.; Hwang, Y.S.

    1992-10-01

    Recent experiments in many devices have provided firm evidence that the edge radial electric field profile differs between L- and H-modes, and that these fields can greatly modify transport in tokamak plasmas. A nonintrusive method for inducing radial electric field based on electron ripple injection is being developed by the CDX-U group. This technique utilizes a pair of special coils to create a local magnetic field ripple to trap the electrons at the edge of the plasma. The trapped electrons then drift into the plasma due to the {del}B drift. An ECH power is applied to accelerate electrons to sufficient perpendicular energy to penetrate into the plasma. Application of ECH power to the trapped electrons should provide the desired 20 A of electron current with electrons of a few keV of energy and v{perpendicular}/v{parallel} {much_gt} 1. A controlled experiment to investigate the physics of ECH aided ripple injection has been designed on CDX-U. With the set of ripple coils designed for CDX-U, a ripple fraction of {delta} ({double_bond} {del}B/B{sub av}) {approximately} 5% is attainable. At this ripple fraction, electrons are trapped if v{perpendicular}/v{parallel} {much_gt} 1> (2{delta}){sup {minus}{1/2}} {approx}3. A resonant cavity box was fabricated for efficient heating of the trapped electrons. It is also capable of measuring the effect of the field ripple in conjunction with trapped electrons. Some preliminary results are given.

  13. Transport of electrons in monolithic hot electron Si transistors

    NASA Astrophysics Data System (ADS)

    Berz, F.

    1986-12-01

    The transport of electrons across the base of monolithic hot electron transistors is studied using a simplified model. The base is assumed to be limited by abrupt barriers and no account is taken of backscattering from the collector region. The collisions in the base are considered to be of only one type which represents an average between interactions with optical and acoustic phonons. A fundamental part in the analysis is played by the function PEX( i, x), ( i = 1, 2, …) which gives the total probability of exit into the collector of an electron whose ith collision occurs at a point of abscissa x within the base. The function PEX( i, x) is determined iteratively for decreasing values of i, using the theorem of compound probabilities, and from there the transport factor α across the base is derived. Programs have been written to this effect, and the results are illustrated by means of examples which demonstrate the effect on the transport factor α of the various parameters of the device, and show some comparisons with a previous theory[4].

  14. Radiation Hardened Electronics for Extreme Environments

    NASA Technical Reports Server (NTRS)

    Keys, Andrew S.; Watson, Michael D.

    2007-01-01

    The Radiation Hardened Electronics for Space Environments (RHESE) project consists of a series of tasks designed to develop and mature a broad spectrum of radiation hardened and low temperature electronics technologies. Three approaches are being taken to address radiation hardening: improved material hardness, design techniques to improve radiation tolerance, and software methods to improve radiation tolerance. Within these approaches various technology products are being addressed including Field Programmable Gate Arrays (FPGA), Field Programmable Analog Arrays (FPAA), MEMS Serial Processors, Reconfigurable Processors, and Parallel Processors. In addition to radiation hardening, low temperature extremes are addressed with a focus on material and design approaches.

  15. Logistics, electronic commerce, and the environment

    NASA Astrophysics Data System (ADS)

    Sarkis, Joseph; Meade, Laura; Talluri, Srinivas

    2002-02-01

    Organizations realize that a strong supporting logistics or electronic logistics (e-logistics) function is important from both commercial and consumer perspectives. The implications of e-logistics models and practices cover the forward and reverse logistics functions of organizations. They also have direct and profound impact on the natural environment. This paper will focus on a discussion of forward and reverse e-logistics and their relationship to the natural environment. After discussion of the many pertinent issues in these areas, directions of practice and implications for study and research are then described.

  16. Conditioner for a helically transported electron beam

    SciTech Connect

    Wang, Changbiao

    1992-05-01

    The kinetic theory is developed to investigate a conditioner for a helically transported electron beam. Linear expressions for axial velocity spread are derived. Numerical simulation is used to check the theoretical results and examine nonlinear aspects of the conditioning process. The results show that in the linear regime the action of the beam conditioner on a pulsed beam mainly depends on the phase at which the beam enters the conditioner and depends only slightly on the operating wavelength. In the nonlinear regime, however, the action of the conditioner strongly depends on the operating wavelength and only slightly upon the entrance phase. For a properly chosen operating wavelength, a little less than the electron`s relativistic cyclotron wavelength, the conditioner can decrease the axial velocity spread of a pulsed beam down to less than one-third of its initial value.

  17. The AE-8 trapped electron model environment

    NASA Technical Reports Server (NTRS)

    Vette, James I.

    1991-01-01

    The machine sensible version of the AE-8 electron model environment was completed in December 1983. It has been sent to users on the model environment distribution list and is made available to new users by the National Space Science Data Center (NSSDC). AE-8 is the last in a series of terrestrial trapped radiation models that includes eight proton and eight electron versions. With the exception of AE-8, all these models were documented in formal reports as well as being available in a machine sensible form. The purpose of this report is to complete the documentation, finally, for AE-8 so that users can understand its construction and see the comparison of the model with the new data used, as well as with the AE-4 model.

  18. Electron transport parameters in NF3

    NASA Astrophysics Data System (ADS)

    Lisovskiy, V.; Yegorenkov, V.; Ogloblina, P.; Booth, J.-P.; Martins, S.; Landry, K.; Douai, D.; Cassagne, V.

    2014-03-01

    We present electron transport parameters (the first Townsend coefficient, the dissociative attachment coefficient, the fraction of electron energy lost by collisions with NF3 molecules, the average and characteristic electron energy, the electron mobility and the drift velocity) in NF3 gas calculated from published elastic and inelastic electron-NF3 collision cross-sections using the BOLSIG+ code. Calculations were performed for the combined RB (Rescigno 1995 Phys. Rev. E 52 329, Boesten et al 1996 J. Phys. B: At. Mol. Opt. Phys. 29 5475) momentum-transfer cross-section, as well as for the JB (Joucoski and Bettega 2002 J. Phys. B: At. Mol. Opt. Phys. 35 783) momentum-transfer cross-section. In addition, we have measured the radio frequency (rf) breakdown curves for various inter-electrode gaps and rfs, and from these we have determined the electron drift velocity in NF3 from the location of the turning point in these curves. These drift velocity values are in satisfactory agreement with those calculated by the BOLSIG+ code employing the JB momentum-transfer cross-section.

  19. Electronic transport in graphene-based heterostructures

    SciTech Connect

    Tan, J. Y.; Avsar, A.; Balakrishnan, J.; Taychatanapat, T.; O'Farrell, E. C. T.; Eda, G.; Castro Neto, A. H.; Koon, G. K. W.; Özyilmaz, B.; Watanabe, K.; Taniguchi, T.

    2014-05-05

    While boron nitride (BN) substrates have been utilized to achieve high electronic mobilities in graphene field effect transistors, it is unclear how other layered two dimensional (2D) crystals influence the electronic performance of graphene. In this Letter, we study the surface morphology of 2D BN, gallium selenide (GaSe), and transition metal dichalcogenides (tungsten disulfide (WS{sub 2}) and molybdenum disulfide (MoS{sub 2})) crystals and their influence on graphene's electronic quality. Atomic force microscopy analysis shows that these crystals have improved surface roughness (root mean square value of only ∼0.1 nm) compared to conventional SiO{sub 2} substrate. While our results confirm that graphene devices exhibit very high electronic mobility (μ) on BN substrates, graphene devices on WS{sub 2} substrates (G/WS{sub 2}) are equally promising for high quality electronic transport (μ ∼ 38 000 cm{sup 2}/V s at room temperature), followed by G/MoS{sub 2} (μ ∼ 10 000 cm{sup 2}/V s) and G/GaSe (μ ∼ 2200 cm{sup 2}/V s). However, we observe a significant asymmetry in electron and hole conduction in G/WS{sub 2} and G/MoS{sub 2} heterostructures, most likely due to the presence of sulphur vacancies in the substrate crystals. GaSe crystals are observed to degrade over time even under ambient conditions, leading to a large hysteresis in graphene transport making it a less suitable substrate.

  20. Distribution of tunnelling times for quantum electron transport

    NASA Astrophysics Data System (ADS)

    Rudge, Samuel L.; Kosov, Daniel S.

    2016-03-01

    In electron transport, the tunnelling time is the time taken for an electron to tunnel out of a system after it has tunnelled in. We define the tunnelling time distribution for quantum processes in a dissipative environment and develop a practical approach for calculating it, where the environment is described by the general Markovian master equation. We illustrate the theory by using the rate equation to compute the tunnelling time distribution for electron transport through a molecular junction. The tunnelling time distribution is exponential, which indicates that Markovian quantum tunnelling is a Poissonian statistical process. The tunnelling time distribution is used not only to study the quantum statistics of tunnelling along the average electric current but also to analyse extreme quantum events where an electron jumps against the applied voltage bias. The average tunnelling time shows distinctly different temperature dependence for p- and n-type molecular junctions and therefore provides a sensitive tool to probe the alignment of molecular orbitals relative to the electrode Fermi energy.

  1. Dissipative electronic transport through double quantum dots irradiated with microwaves

    NASA Astrophysics Data System (ADS)

    Brandes, Tobias; Aguado, Ramon; Platero, Gloria

    2003-03-01

    Double quantum dots in the strong Coulomb blockade regime are realizations of two-level systems defined from two tunnel--splitted ground states, which are separated by a large energy gap from the remaining many--particle states. The interactions between electrons and bosonic degrees of freedom (photons, phonons) in these systems can be tested and manipulated in electronic transport experiments [1]. Monochromatic classical radiation (AC fields, microwaves) gives rise to various non-linear effects such as photo-sidebands or dynamical localization (coherent supression of tunneling) that show up in the time-averaged, stationary electronic current [2]. On the other hand, quantum noise of a dissipative environment strongly influences the transport properties of coupled quantum dots [3,4]. In this contribution, we quantitatively investigate the combined influence of a classical, monochromatic time-dependent AC field and a dissipative boson environment on the non-linear transport through a double quantum dot. We develop a Floquet-like theory [5] that takes into account the effect of the electron reservoirs (leads) and can be numerically evaluated for arbitrary strong AC fields and arbitrary boson environment. In limiting cases we reproduce previous analytical results (polaron tunneling, Tien-Gordon formula). [1] T. Fujisawa, T. H. Oosterkamp, W. G. van der Wiel, B. W. Broer, R. Aguado, S. Tarucha, and L. P. Kouwenhoven, Science 282, 932 (1998); R. H. Blick, D. Pfannkuche, R. J. Haug, K. v. Klitzing, and K. Eberl, Phys. Rev. Lett. 80, 4032 (1998). [2] T. H. Stoof, Yu. V. Nazarov, Phys. Rev. B 53, 1050 (1996). [3] T. Brandes, B. Kramer, Phys. Rev. Lett. 83, 3021 (1999); T. Brandes, F. Renzoni, R. H. Blick, Phys. Rev. B 64, 035319 (2001); T. Brandes, T. Vorrath, Phys. Rev. B 66, 075341 (2002). [4] R. Aguado and L. P. Kouwenhoven, Phys. Rev. Lett, 84, 1986 (2000). [5] M. Grifoni, P. Hänggi, Phys. Rep. 304, 229 (1998).

  2. Electronic transport properties of silicon clusters

    NASA Astrophysics Data System (ADS)

    Matsuura, Yukihito

    2016-02-01

    The electronic transport properties of silicon clusters were examined via theoretical calculations using the first-principles method. Additionally, p-type doping and n-type doping were analyzed by calculating conductance and current of boron- and phosphorus-doped silicon clusters. The p-type doping and n-type doping provided a new transmission peak at an energy level around the Fermi level to increase conductance. Furthermore, simultaneous boron and phosphorus doping resulted in noticeable rectifying characteristics, with the current drive in forward bias being three times higher than that in the reverse bias. A p-n junction was achieved even on a molecular scale.

  3. Inelastic electron transport in granular arrays

    SciTech Connect

    Altland, A.; Glazman, L.I.; Kamenev, A.; Meyer, J.S. . E-mail: jmeyer@mps.ohio-state.edu

    2006-11-15

    Transport properties of granular systems are governed by Coulomb blockade effects caused by the discreteness of the electron charge. We show that, in the limit of vanishing mean level spacing on the grains, the low-temperature behavior of 1d and 2d arrays is insulating at any inter-grain coupling (characterized by a dimensionless conductance g). In 2d and g >> 1, there is a sharp Berezinskii-Kosterlitz-Thouless crossover to the conducting phase at a certain temperature, T {sub BKT}. These results are obtained by applying an instanton analysis to map the conventional 'phase' description of granular arrays onto the dual 'charge' representation.

  4. Inelastic electron transport in granular arrays.

    SciTech Connect

    Altland, A.; Glazman, L. I.; Kamenev, A.; Meyer, J. S.; Materials Science Division; Univ. zu Koln; Univ. Minnesota; Ohio State Univ.

    2006-01-01

    Transport properties of granular systems are governed by Coulomb blockade effects caused by the discreteness of the electron charge. We show that, in the limit of vanishing mean level spacing on the grains, the low-temperature behavior of 1d and 2d arrays is insulating at any inter-grain coupling (characterized by a dimensionless conductance g). In 2d and g 1, there is a sharp Berezinskii-Kosterlitz-Thouless crossover to the conducting phase at a certain temperature, T{sub BKT}. These results are obtained by applying an instanton analysis to map the conventional 'phase' description of granular arrays onto the dual 'charge' representation.

  5. Electron heat transport down steep temperature gradients

    SciTech Connect

    Matte, J.P.; Virmont, J.

    1982-12-27

    Electron heat transport is studied by numerically solving the Fokker-Planck equation, with a spherical harmonic representation of the distribution function. The first two terms (f/sub 0/, f/sub 1/) suffice, even in steep temperature gradients. Deviations from the Spitzer-Haerm law appear for lambda/L/sub T/ ((mean free path)/(temperature gradient length))> or approx. =0.01, as a result of non-Maxwellian f/sub 0/. For lambda/L/sub T/> or approx. =1, the heat flux is (1/3) of the free-streaming value. In intermediate cases, a harmonic law describes well the hottest part of the plasma.

  6. Electronic transport properties of (fluorinated) metal phthalocyanine

    NASA Astrophysics Data System (ADS)

    Fadlallah, M. M.; Eckern, U.; Romero, A. H.; Schwingenschlögl, U.

    2016-01-01

    The magnetic and transport properties of the metal phthalocyanine (MPc) and F16MPc (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ag) families of molecules in contact with S-Au wires are investigated by density functional theory within the local density approximation, including local electronic correlations on the central metal atom. The magnetic moments are found to be considerably modified under fluorination. In addition, they do not depend exclusively on the configuration of the outer electronic shell of the central metal atom (as in isolated MPc and F16MPc) but also on the interaction with the leads. Good agreement between the calculated conductance and experimental results is obtained. For M = Ag, a high spin filter efficiency and conductance is observed, giving rise to a potentially high sensitivity for chemical sensor applications.

  7. Conditioner for a helically transported electron beam

    SciTech Connect

    Wang, Changbiao.

    1992-05-01

    The kinetic theory is developed to investigate a conditioner for a helically transported electron beam. Linear expressions for axial velocity spread are derived. Numerical simulation is used to check the theoretical results and examine nonlinear aspects of the conditioning process. The results show that in the linear regime the action of the beam conditioner on a pulsed beam mainly depends on the phase at which the beam enters the conditioner and depends only slightly on the operating wavelength. In the nonlinear regime, however, the action of the conditioner strongly depends on the operating wavelength and only slightly upon the entrance phase. For a properly chosen operating wavelength, a little less than the electron's relativistic cyclotron wavelength, the conditioner can decrease the axial velocity spread of a pulsed beam down to less than one-third of its initial value.

  8. Lithium electronic environments in rechargeable battery electrodes

    NASA Astrophysics Data System (ADS)

    Hightower, Adrian

    This work investigates the electronic environments of lithium in the electrodes of rechargeable batteries. The use of electron energy-loss spectroscopy (EELS) in conjunction with transmission electron microscopy (TEM) is a novel approach, which when coupled with conventional electrochemical experiments, yield a thorough picture of the electrode interior. Relatively few EELS experiments have been preformed on lithium compounds owing to their reactivity. Experimental techniques were established to minimize sample contamination and control electron beam damage to studied compounds. Lithium hydroxide was found to be the most common product of beam damaged lithium alloys. Under an intense electron beam, halogen atoms desorbed by radiolysis in lithium halides. EELS spectra from a number of standard lithium compounds were obtained in order to identify the variety of spectra encountered in lithium rechargeable battery electrodes. Lithium alloys all displayed characteristically broad Li K-edge spectra, consistent with transitions to continuum states. Transitions to bound states were observed in the Li K and oxygen K-edge spectra of lithium oxides. Lithium halides were distinguished by their systematic chemical shift proportional to the anion electronegativity. Good agreement was found with measured lithium halide spectra and electron structure calculations using a self-consistant multiscattering code. The specific electrode environments of LiC6, LiCoO2, and Li-SnO were investigated. Contrary to published XPS predictions, lithium in intercalated graphite was determined to be in more metallic than ionic. We present the first experimental evidence of charge compensation by oxygen ions in deintercalated LiCoO2. Mossbauer studies on cycled Li-SnO reveal severely defective structures on an atomic scale. Metal hydride systems are presented in the appendices of this thesis. The mechanical alloying of immiscible Fe and Mg powders resulted in single-phase bcc alloys of less than 20

  9. Status of electron transport in MCNP{trademark}

    SciTech Connect

    Hughes, H.G.

    1995-09-01

    In recent years, an ongoing project within the radiation transport group (XTM) at Los Alamos National Laboratory has been the implementation and validation of an electron transport capability in the Monte Carlo code NICNP. In this paper the authors document the continuous-energy electron transport methods currently in use in MCNP, and describes a recent improvement of the energy-loss straggling algorithm. MCNP also supports electron transport calculations in a multigroup mode.

  10. Electronic transport of recrystallized freestanding graphene nanoribbons.

    PubMed

    Qi, Zhengqing John; Daniels, Colin; Hong, Sung Ju; Park, Yung Woo; Meunier, Vincent; Drndić, Marija; Johnson, A T Charlie

    2015-01-01

    The use of graphene and other two-dimensional materials in next-generation electronics is hampered by the significant damage caused by conventional lithographic processing techniques employed in device fabrication. To reduce the density of defects and increase mobility, Joule heating is often used since it facilitates lattice reconstruction and promotes self-repair. Despite its importance, an atomistic understanding of the structural and electronic enhancements in graphene devices enabled by current annealing is still lacking. To provide a deeper understanding of these mechanisms, atomic recrystallization and electronic transport in graphene nanoribbon (GNR) devices are investigated using a combination of experimental and theoretical methods. GNR devices with widths below 10 nm are defined and electrically measured in situ within the sample chamber of an aberration-corrected transmission electron microscope. Immediately after patterning, we observe few-layer polycrystalline GNRs with irregular sp(2)-bonded edges. Continued structural recrystallization toward a sharp, faceted edge is promoted by increasing application of Joule heat. Monte Carlo-based annealing simulations reveal that this is a result of concentrated local currents at lattice defects, which in turn promotes restructuring of unfavorable edge structures toward an atomically sharp state. We establish that intrinsic conductance doubles to 2.7 e(2)/h during the recrystallization process following an almost 3-fold reduction in device width, which is attributed to improved device crystallinity. In addition to the observation of consistent edge bonding in patterned GNRs, we further motivate the use of bonded bilayer GNRs for future nanoelectronic components by demonstrating how electronic structure can be tailored by an appropriate modification of the relative twist angle of the bonded bilayer.

  11. Electronic Cigarette Topography in the Natural Environment.

    PubMed

    Robinson, R J; Hensel, E C; Morabito, P N; Roundtree, K A

    2015-01-01

    This paper presents the results of a clinical, observational, descriptive study to quantify the use patterns of electronic cigarette users in their natural environment. Previously published work regarding puff topography has been widely indirect in nature, and qualitative rather than quantitative, with the exception of three studies conducted in a laboratory environment for limited amounts of time. The current study quantifies the variation in puffing behaviors among users as well as the variation for a given user throughout the course of a day. Puff topography characteristics computed for each puffing session by each subject include the number of subject puffs per puffing session, the mean puff duration per session, the mean puff flow rate per session, the mean puff volume per session, and the cumulative puff volume per session. The same puff topography characteristics are computed across all puffing sessions by each single subject and across all subjects in the study cohort. Results indicate significant inter-subject variability with regard to puffing topography, suggesting that a range of representative puffing topography patterns should be used to drive machine-puffed electronic cigarette aerosol evaluation systems.

  12. Ion age transport: developing devices beyond electronics

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2014-03-01

    There is more to current devices than conventional electronics. Increasingly research into the controlled movement of ions and molecules is enabling a range of new technologies. For example, as Weihua Guan, Sylvia Xin Li and Mark Reed at Yale University explain, 'It offers a unique opportunity to integrate wet ionics with dry electronics seamlessly'. In this issue they provide an overview of voltage-gated ion and molecule transport in engineered nanochannels. They cover the theory governing these systems and fabrication techniques, as well as applications, including biological and chemical analysis, and energy conversion [1]. Studying the movement of particles in nanochannels is not new. The transport of materials in rock pores led Klinkenberg to describe an analogy between diffusion and electrical conductivity in porous rocks back in 1951 [2]. And already in 1940, Harold Abramson and Manuel Gorin noted that 'When an electric current is applied across the living human skin, the skin may be considered to act like a system of pores through which transfer of substances like ragweed pollen extract may be achieved both by electrophoretic and by diffusion phenomena' [3]. Transport in living systems through pore structures on a much smaller scale has attracted a great deal of research in recent years as well. The selective transport of ions and small organic molecules across the cell membrane facilitates a number of functions including communication between cells, nerve conduction and signal transmission. Understanding these processes may benefit a wide range of potential applications such as selective separation, biochemical sensing, and controlled release and drug delivery processes. In Germany researchers have successfully demonstrated controlled ionic transport through nanopores functionalized with amine-terminated polymer brushes [4]. The polymer nanobrushes swell and shrink in response to changes in temperature, thus opening and closing the nanopore passage to ionic

  13. Ion age transport: developing devices beyond electronics

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2014-03-01

    There is more to current devices than conventional electronics. Increasingly research into the controlled movement of ions and molecules is enabling a range of new technologies. For example, as Weihua Guan, Sylvia Xin Li and Mark Reed at Yale University explain, 'It offers a unique opportunity to integrate wet ionics with dry electronics seamlessly'. In this issue they provide an overview of voltage-gated ion and molecule transport in engineered nanochannels. They cover the theory governing these systems and fabrication techniques, as well as applications, including biological and chemical analysis, and energy conversion [1]. Studying the movement of particles in nanochannels is not new. The transport of materials in rock pores led Klinkenberg to describe an analogy between diffusion and electrical conductivity in porous rocks back in 1951 [2]. And already in 1940, Harold Abramson and Manuel Gorin noted that 'When an electric current is applied across the living human skin, the skin may be considered to act like a system of pores through which transfer of substances like ragweed pollen extract may be achieved both by electrophoretic and by diffusion phenomena' [3]. Transport in living systems through pore structures on a much smaller scale has attracted a great deal of research in recent years as well. The selective transport of ions and small organic molecules across the cell membrane facilitates a number of functions including communication between cells, nerve conduction and signal transmission. Understanding these processes may benefit a wide range of potential applications such as selective separation, biochemical sensing, and controlled release and drug delivery processes. In Germany researchers have successfully demonstrated controlled ionic transport through nanopores functionalized with amine-terminated polymer brushes [4]. The polymer nanobrushes swell and shrink in response to changes in temperature, thus opening and closing the nanopore passage to ionic

  14. Discovering Narrative Transportation in an Education Environment

    ERIC Educational Resources Information Center

    Miner, Eric F.

    2014-01-01

    Narrative transportation occurs when people become emotionally immersed in stories, such that they feel imaginatively conveyed into story worlds. This study investigated the lived experiences of students who encountered narrative transportation in a college classroom. It is of interest to psychologists and educational practitioners because…

  15. Multidimensional electron-photon transport with standard discrete ordinates codes

    SciTech Connect

    Drumm, C.R.

    1997-04-01

    A method is described for generating electron cross sections that are comparable with standard discrete ordinates codes without modification. There are many advantages of using an established discrete ordinates solver, e.g. immediately available adjoint capability. Coupled electron-photon transport capability is needed for many applications, including the modeling of the response of electronics components to space and man-made radiation environments. The cross sections have been successfully used in the DORT, TWODANT and TORT discrete ordinates codes. The cross sections are shown to provide accurate and efficient solutions to certain multidimensional electron-photon transport problems. The key to the method is a simultaneous solution of the continuous-slowing-down (CSD) portion and elastic-scattering portion of the scattering source by the Goudsmit-Saunderson theory. The resulting multigroup-Legendre cross sections are much smaller than the true scattering cross sections that they represent. Under certain conditions, the cross sections are guaranteed positive and converge with a low-order Legendre expansion.

  16. Multidimensional electron-photon transport with standard discrete ordinates codes

    SciTech Connect

    Drumm, C.R.

    1997-09-01

    A method is described for generating electron cross sections that are compatible with standard discrete ordinates codes without modification. There are many advantages to using an established discrete ordinates solver, e.g., immediately available adjoint capability. Coupled electron-photon transport capability is needed for many applications, including the modeling of the response of electronics components to space and synthetic radiation environments. The cross sections have been successfully used in the DORT, TWODANT, and TORT discrete ordinates codes. The cross sections are shown to provide accurate and efficient solutions to certain multidimensional electron-photon transport problems. The key to the method is a simultaneous solution of the continuous-slowing-down and elastic-scattering portions of the scattering source by the Goudsmit-Saunderson theory. The resulting multigroup-Legendre cross sections are much smaller than the true scattering cross sections that they represent. Under certain conditions, the cross sections are guaranteed positive and converge with a low-order Legendre expansion.

  17. Transportation and the Environment. Publication No. 74-2.

    ERIC Educational Resources Information Center

    Fagan, James S.

    The increasingly important role of transportation and its environmental impact is given major emphasis in this curriculum unit for secondary students. Four purposes of this unit are to describe and show (1) the historical development of transportation in America; (2) the effect of current transportation practices upon the environment; (3) some…

  18. Electronic transport and dynamics in correlated heterostructures

    NASA Astrophysics Data System (ADS)

    Mazza, G.; Amaricci, A.; Capone, M.; Fabrizio, M.

    2015-05-01

    We investigate by means of the time-dependent Gutzwiller approximation the transport properties of a strongly correlated slab subject to Hubbard repulsion and connected with to two metallic leads kept at a different electrochemical potential. We focus on the real-time evolution of the electronic properties after the slab is connected to the leads and consider both metallic and Mott insulating slabs. When the correlated slab is metallic, the system relaxes to a steady state that sustains a finite current. The zero-bias conductance is finite and independent of the degree of correlations within the slab as long as the system remains metallic. On the other hand, when the slab is in a Mott insulating state, the external bias leads to currents that are exponentially activated by charge tunneling across the Mott-Hubbard gap, consistent with the Landau-Zener dielectric breakdown scenario.

  19. Transportation: Environment, energy and the economy

    SciTech Connect

    Petrakis, L.

    1993-01-11

    In the US, the transportation sector consumes over one quarter of the entire energy used, almost in its entirety as petroleum products, and in quantities greater than the total US domestic oil production. The transportation sector is responsible for a significant fraction of all emissions that either prevent US cities from achieving compliance with EPA air quality standards or have serious global change implications. Finally, the GDP (Gross Domestic Product) and employment due to the sector are low and incommensurate with the high fraction of energy that the transportation sector consumes. We examine below this situation in some detail and make recommendations for improvements.

  20. Effects of Cu deficiency on photosynthetic electron transport

    SciTech Connect

    Droppa, M.; Terry, N.; Horvath, G.

    1984-04-01

    The role of copper (Cu) in photosynthetic electron transport was explored by using Cu deficiency in sugar beet as an experimental approach. Copper influenced electron transport at two sites in addition to plastocyanin. Under mild deficiency (0.84 nmol of Cu per cm/sup 2/ of leaf area), electron transport between the two photosystems (PS) is inhibited but not electron transport within PS I or PS II measured separately. The chlorophyll/plastoquinone ratio was normal in Cu-deficient plants. However, the breakpoint in the Arrhenius plot of electron transport was shifted towards a higher temperature. It is concluded that Cu is necessary to maintain the appropriate membrane fluidity to ensure the mobility of plastoquinone molecules to transfer electrons between the two photosystems. Under severe deficiency (0.22 nmol of Cu per cm/sup 2/ of leaf area) both PS II and PS I electron transports were inhibited and to the same extent. PS II electron transport activity could not be restored by adding artifical electron donors. Polypeptides with M/sub r/s of 28,000 and 13,500 were missing in Cu-deficient chloroplast membranes. In PS II particles prepared from normal chloroplasts of spinach, 2 atoms of Cu per reaction center are present. We conclude that Cu influences PS II electron transport either directly, by participation in electron transfer as a constituent of an electron carrier, or indirectly, via the polypeptide composition of the membrane in the PS II complex.

  1. Electron scattering and transport in liquid argon

    SciTech Connect

    Boyle, G. J.; Cocks, D. G.; White, R. D.; McEachran, R. P.

    2015-04-21

    The transport of excess electrons in liquid argon driven out of equilibrium by an applied electric field is revisited using a multi-term solution of Boltzmann’s equation together with ab initio liquid phase cross-sections calculated using the Dirac-Fock scattering equations. The calculation of liquid phase cross-sections extends previous treatments to consider multipole polarisabilities and a non-local treatment of exchange, while the accuracy of the electron-argon potential is validated through comparison of the calculated gas phase cross-sections with experiment. The results presented highlight the inadequacy of local treatments of exchange that are commonly used in liquid and cluster phase cross-section calculations. The multi-term Boltzmann equation framework accounting for coherent scattering enables the inclusion of the full anisotropy in the differential cross-section arising from the interaction and the structure factor, without an a priori assumption of quasi-isotropy in the velocity distribution function. The model, which contains no free parameters and accounts for both coherent scattering and liquid phase screening effects, was found to reproduce well the experimental drift velocities and characteristic energies.

  2. Interstate waste transport -- Emotions, energy, and environment

    SciTech Connect

    Elcock, D.

    1993-12-31

    This report applies quantitative analysis to the debate of waste transport and disposal. Moving from emotions and politics back to numbers, this report estimates potential energy, employment and environmental impacts associated with disposing a ton of municipal solid waste under three different disposal scenarios that reflect interstate and intrastate options. The results help provide a less emotional, more quantitative look at interstate waste transport restrictions.

  3. Interstate waste transport -- Emotions, energy, and environment

    SciTech Connect

    Elcock, D.

    1993-01-01

    This report applies quantitative analysis to the debate of waste transport and disposal. Moving from emotions and politics back to numbers, this report estimates potential energy, employment and environmental impacts associated with disposing a ton of municipal solid waste under three different disposal scenarios that reflect interstate and intrastate options. The results help provide a less emotional, more quantitative look at interstate waste transport restrictions.

  4. Vibrationally dependent electron-electron interactions in resonant electron transport through single-molecule junctions

    NASA Astrophysics Data System (ADS)

    Erpenbeck, A.; Härtle, R.; Bockstedte, M.; Thoss, M.

    2016-03-01

    We investigate the role of electronic-vibrational coupling in resonant electron transport through single-molecule junctions, taking into account that the corresponding coupling strengths may depend on the charge and excitation state of the molecular bridge. Within an effective-model Hamiltonian approach for a molecule with multiple electronic states, this requires to extend the commonly used model and include vibrationally dependent electron-electron interaction. We use Born-Markov master equation methods and consider selected models to exemplify the effect of the additional interaction on the transport characteristics of a single-molecule junction. In particular, we show that it has a significant influence on local cooling and heating mechanisms, it may result in negative differential resistance, and it may cause pronounced asymmetries in the conductance map of a single-molecule junction.

  5. Designing a beam transport system for RHIC's electron lens

    SciTech Connect

    Gu, X.; Pikin, A.; Okamura, M.; Fischer, W.; Luo, Y.; Gupta, R.; Hock, J.; Raparia, D.

    2011-03-28

    We designed two electron lenses to apply head-on beam-beam compensation for RHIC; they will be installed near IP10. The electron-beam transport system is an important subsystem of the entire electron-lens system. Electrons are transported from the electron gun to the main solenoid and further to the collector. The system must allow for changes of the electron beam size inside the superconducting magnet, and for changes of the electron position by 5 mm in the horizontal- and vertical-planes.

  6. Transition in Electron Transport in a Cylindrical Hall Thruster

    SciTech Connect

    J.B. Parker, Y. Raitses, and N.J. Fisch

    2010-06-02

    Through the use of high-speed camera and Langmuir probe measurements in a cylindrical Hall thruster, we report the discovery of a rotating spoke of increased plasma density and light emission which correlates with increased electron transport across the magnetic field. As cathode electron emission is increased, a sharp transition occurs where the spoke disappears and electron transport decreases. This suggests that a significant fraction of the electron current might be directed through the spoke.

  7. Transition in electron transport in a cylindrical Hall thruster

    SciTech Connect

    Parker, J. B.; Raitses, Y.; Fisch, N. J.

    2010-08-30

    Through the use of high-speed camera and Langmuir probe measurements in a cylindrical Hall thruster, we report the discovery of a rotating spoke of increased plasma density and light emission which correlates with increased electron transport across the magnetic field. As cathode electron emission is increased, a sharp transition occurs where the spoke disappears and electron transport decreases. This suggests that a significant fraction of the electron current might be directed through the spoke.

  8. Electronic and Ionic Transport Dynamics in Organolead Halide Perovskites.

    PubMed

    Li, Dehui; Wu, Hao; Cheng, Hung-Chieh; Wang, Gongming; Huang, Yu; Duan, Xiangfeng

    2016-07-26

    Ion migration has been postulated as the underlying mechanism responsible for the hysteresis in organolead halide perovskite devices. However, the electronic and ionic transport dynamics and how they impact each other in organolead halide perovskites remain elusive to date. Here we report a systematic investigation of the electronic and ionic transport dynamics in organolead halide perovskite microplate crystals and thin films using temperature-dependent transient response measurements. Our study reveals that thermally activated ionic and electronic conduction coexist in perovskite devices. The extracted activation energies suggest that the electronic transport is easier, but ions migrate harder in microplates than in thin films, demonstrating that the crystalline quality and grain boundaries can fundamentally modify electronic and ionic transport in perovskites. These findings offer valuable insight on the electronic and ionic transport dynamics in organolead halide perovskites, which is critical for optimizing perovskite devices with reduced hysteresis and improved stability and efficiency.

  9. The induction of microsomal electron transport enzymes.

    PubMed

    Waterman, M R; Estabrook, R W

    1983-01-01

    Liver endoplasmic reticulum contains as NADPH-dependent electron transport complex where the family of hemeproteins, termed cytochrome P-450, serve as catalysts for the oxidation of a variety of different organic chemicals. The content and inventory of the types of cytochrome P-450 is readily modified following in vivo treatment of animals with 'inducing agents' such as barbiturates, steroids and polycyclic hydrocarbons. Recent studies have applied the methods of molecular biology to evaluate changes in the transcription and translation of genomic information occurring concomitant with the initiation of synthesis of various types of cytochrome P-450. The ability to isolate unique cytochrome P-450 proteins and to prepare specific antibodies now permits the study of in vitro translation of mRNA and the preparation of specific cDNAs. The present review summarizes the historic background leading to current concepts of cytochrome P-450 induction and describes recent advances in our knowledge of the regulation of cytochrome P-450 synthesis in the liver. PMID:6353196

  10. 4. ENVIRONMENT, FROM SOUTHEAST, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. ENVIRONMENT, FROM SOUTHEAST, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE NO. 6023 CARRYING STATE ROUTE 646 (ADEN ROAD) OVER RAILROAD TRACKS - Virginia Department of Transportation Bridge No. 6023, Spanning Norfolk Southern tracks at State Route 646, Nokesville, Prince William County, VA

  11. 1. ENVIRONMENT, FROM NORTHWEST, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. ENVIRONMENT, FROM NORTHWEST, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE NO. 6051 CARRYING STATE ROUTE 673 (FEATHERBOTTOM ROAD) ACROSS CATOCTIN CREEK - Virginia Department of Transportation Bridge No. 6051, Spanning Catoctin Creek at State Route 673 (Featherbottom Road), Waterford, Loudoun County, VA

  12. 3. ENVIRONMENT, FROM SOUTH, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. ENVIRONMENT, FROM SOUTH, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE NO. 6051 CARRYING STATE ROUTE 673 (FEATHERBOTTOM ROAD) OVER CATOCTIN CREEK - Virginia Department of Transportation Bridge No. 6051, Spanning Catoctin Creek at State Route 673 (Featherbottom Road), Waterford, Loudoun County, VA

  13. 4. ENVIRONMENT, FROM EAST, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. ENVIRONMENT, FROM EAST, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE NO. 6051 CARRYING STATE ROUTE 673 (FEATHERBOTTOM ROAD) OVER CATOCTIN CREEK - Virginia Department of Transportation Bridge No. 6051, Spanning Catoctin Creek at State Route 673 (Featherbottom Road), Waterford, Loudoun County, VA

  14. 2. ENVIRONMENT, FROM NORTH, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. ENVIRONMENT, FROM NORTH, SHOWING VIRGINIA DEPARTMENT OF TRANSPORTATION BRIDGE NO. 6051 CARRYING STATE ROUTE 673 (FEATHERBOTTOM ROAD) OVER CATOCTIN CREEK - Virginia Department of Transportation Bridge No. 6051, Spanning Catoctin Creek at State Route 673 (Featherbottom Road), Waterford, Loudoun County, VA

  15. An update of spacecraft dynamic environments induced by ground transportation

    NASA Technical Reports Server (NTRS)

    Oconnell, N. R.

    1985-01-01

    An update to a spacecraft transportation dynamic environments data base was developed based on data from recent transportation of spacecrafts. Vibration levels are significantly lower than those measured in 1966, while the shock response spectra are nearly the same. Ground shipping criteria and shipping practices, which have been very successful in preventing damage, are also summarized.

  16. Operating systems in the air transportation environment.

    NASA Technical Reports Server (NTRS)

    Cherry, G. W.

    1971-01-01

    Consideration of the problems facing air transport at present, and to be expected in the future. In the Northeast Corridor these problems involve community acceptance, airway and airport congestion and delays, passenger acceptance, noise reduction, and improvements in low-density short-haul economics. In the development of a superior short-haul operating system, terminal-configured vs cruise-configured vehicles are evaluated. CTOL, STOL, and VTOL aircraft of various types are discussed. In the field of noise abatement, it is shown that flight procedural techniques are capable of supplementing ?quiet engine' technology.

  17. Electron transport theory in magnetic nanostructures

    NASA Astrophysics Data System (ADS)

    Choy, Tat-Sang

    Magnetic nanostructure has been a new trend because of its application in making magnetic sensors, magnetic memories, and magnetic reading heads in hard disks drives. Although a variety of nanostructures have been realized in experiments in recent years by innovative sample growth techniques, the theoretical study of these devices remain a challenge. On one hand, atomic scale modeling is often required for studying the magnetic nanostructures; on the other, these structures often have a dimension on the order of one micrometer, which makes the calculation numerically intensive. In this work, we have studied the electron transport theory in magnetic nanostructures, with special attention to the giant magnetoresistance (GMR) structure. We have developed a model that includes the details of the band structure and disorder, both of which are both important in obtaining the conductivity. We have also developed an efficient algorithm to compute the conductivity in magnetic nanostructures. The model and the algorithm are general and can be applied to complicated structures. We have applied the theory to current-perpendicular-to-plane GMR structures and the results agree with experiments. Finally, we have searched for the atomic configuration with the highest GMR using the simulated annealing algorithm. This method is computationally intensive because we have to compute the GMR for 103 to 104 configurations. However it is still very efficient because the number of steps it takes to find the maximum is much smaller than the number of all possible GMR structures. We found that ultra-thin NiCu superlattices have surprisingly large GMR even at the moderate disorder in experiments. This finding may be useful in improving the GMR technology.

  18. The Near-Earth Space Radiation for Electronics Environment

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.; LaBel, K. A.

    2004-01-01

    The earth's space radiation environment is described in terms of: a) charged particles as relevant to effects on spacecraft electronics, b) the nature and distribution of trapped and transiting radiation, and c) their effect on electronic components.

  19. Reverse electron transport effects on NADH formation and metmyoglobin reduction.

    PubMed

    Belskie, K M; Van Buiten, C B; Ramanathan, R; Mancini, R A

    2015-07-01

    The objective was to determine if NADH generated via reverse electron flow in beef mitochondria can be used for electron transport-mediated reduction and metmyoglobin reductase pathways. Beef mitochondria were isolated from bovine hearts (n=5) and reacted with combinations of succinate, NAD, and mitochondrial inhibitors to measure oxygen consumption and NADH formation. Mitochondria and metmyoglobin were reacted with succinate, NAD, and mitochondrial inhibitors to measure electron transport-mediated metmyoglobin reduction and metmyoglobin reductase activity. Addition of succinate and NAD increased oxygen consumption, NADH formation, electron transport-mediated metmyoglobin reduction, and reductase activity (p<0.05). Addition of antimycin A prevented electron flow beyond complex III, therefore, decreasing oxygen consumption and electron transport-mediated metmyoglobin reduction. Addition of rotenone prevented reverse electron flow, increased oxygen consumption, increased electron transport-mediated metmyoglobin reduction, and decreased NADH formation. Succinate and NAD can generate NADH in bovine tissue postmortem via reverse electron flow and this NADH can be used by both electron transport-mediated and metmyoglobin reductase pathways. PMID:25828162

  20. Reverse electron transport effects on NADH formation and metmyoglobin reduction.

    PubMed

    Belskie, K M; Van Buiten, C B; Ramanathan, R; Mancini, R A

    2015-07-01

    The objective was to determine if NADH generated via reverse electron flow in beef mitochondria can be used for electron transport-mediated reduction and metmyoglobin reductase pathways. Beef mitochondria were isolated from bovine hearts (n=5) and reacted with combinations of succinate, NAD, and mitochondrial inhibitors to measure oxygen consumption and NADH formation. Mitochondria and metmyoglobin were reacted with succinate, NAD, and mitochondrial inhibitors to measure electron transport-mediated metmyoglobin reduction and metmyoglobin reductase activity. Addition of succinate and NAD increased oxygen consumption, NADH formation, electron transport-mediated metmyoglobin reduction, and reductase activity (p<0.05). Addition of antimycin A prevented electron flow beyond complex III, therefore, decreasing oxygen consumption and electron transport-mediated metmyoglobin reduction. Addition of rotenone prevented reverse electron flow, increased oxygen consumption, increased electron transport-mediated metmyoglobin reduction, and decreased NADH formation. Succinate and NAD can generate NADH in bovine tissue postmortem via reverse electron flow and this NADH can be used by both electron transport-mediated and metmyoglobin reductase pathways.

  1. Lunar Dust Grain Charging by Electron Impact: Complex Role of Secondary Electron Emissions in Space Environments

    NASA Astrophysics Data System (ADS)

    Abbas, M. M.; Tankosic, D.; Craven, P. D.; LeClair, A. C.; Spann, J. F.

    2010-08-01

    Dust grains in various astrophysical environments are generally charged electrostatically by photoelectric emissions with radiation from nearby sources, or by electron/ion collisions by sticking or secondary electron emissions (SEEs). The high vacuum environment on the lunar surface leads to some unusual physical and dynamical phenomena involving dust grains with high adhesive characteristics, and levitation and transportation over long distances. Knowledge of the dust grain charges and equilibrium potentials is important for understanding a variety of physical and dynamical processes in the interstellar medium, and heliospheric, interplanetary/planetary, and lunar environments. It has been well recognized that the charging properties of individual micron-/submicron-size dust grains are expected to be substantially different from the corresponding values for bulk materials. In this paper, we present experimental results on the charging of individual 0.2-13 μm size dust grains selected from Apollo 11 and 17 dust samples, and spherical silica particles by exposing them to mono-energetic electron beams in the 10-200 eV energy range. The dust charging process by electron impact involving the SEEs discussed is found to be a complex charging phenomenon with strong particle size dependence. The measurements indicate substantial differences between the polarity and magnitude of the dust charging rates of individual small-size dust grains, and the measurements and model properties of corresponding bulk materials. A more comprehensive plan of measurements of the charging properties of individual dust grains for developing a database for realistic models of dust charging in astrophysical and lunar environments is in progress.

  2. Lunary Dust Grain Charging by Electron Impact: Complex Role of Secondary Electron Emissions in Space Environments

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Tankosic, D.; Crave, P. D.; LeClair, A.; Spann, J. F.

    2010-01-01

    Dust grains in various astrophysical environments are generally charged electrostatically by photoelectric emissions with radiation from nearby sources, or by electron/ion collisions by sticking or secondary electron emissions (SEES). The high vacuum environment on the lunar surface leads to some unusual physical and dynamical phenomena involving dust grains with high adhesive characteristics, and levitation and transportation over long distances. Knowledge of the dust grain charges and equilibrium potentials is important for understanding a variety of physical and dynamical processes in the interstellar medium, and heliospheric, interplanetary/ planetary, and lunar environments. It has been well recognized that the charging properties of individual micron-/submicron-size dust grains are expected to be substantially different from the corresponding values for bulk materials. In this paper, we present experimental results on the charging of individual 0.2-13 m size dust grains selected from Apollo 11 and 17 dust samples, and spherical silica particles by exposing them to mono-energetic electron beams in the 10-200 eV energy range. The dust charging process by electron impact involving the SEES discussed is found to be a complex charging phenomenon with strong particle size dependence. The measurements indicate substantial differences between the polarity and magnitude of the dust charging rates of individual small-size dust grains, and the measurements and model properties of corresponding bulk materials. A more comprehensive plan of measurements of the charging properties of individual dust grains for developing a database for realistic models of dust charging in astrophysical and lunar environments is in progress.

  3. LUNAR DUST GRAIN CHARGING BY ELECTRON IMPACT: COMPLEX ROLE OF SECONDARY ELECTRON EMISSIONS IN SPACE ENVIRONMENTS

    SciTech Connect

    Abbas, M. M.; Craven, P. D.; LeClair, A. C.; Spann, J. F.; Tankosic, D.

    2010-08-01

    Dust grains in various astrophysical environments are generally charged electrostatically by photoelectric emissions with radiation from nearby sources, or by electron/ion collisions by sticking or secondary electron emissions (SEEs). The high vacuum environment on the lunar surface leads to some unusual physical and dynamical phenomena involving dust grains with high adhesive characteristics, and levitation and transportation over long distances. Knowledge of the dust grain charges and equilibrium potentials is important for understanding a variety of physical and dynamical processes in the interstellar medium, and heliospheric, interplanetary/planetary, and lunar environments. It has been well recognized that the charging properties of individual micron-/submicron-size dust grains are expected to be substantially different from the corresponding values for bulk materials. In this paper, we present experimental results on the charging of individual 0.2-13 {mu}m size dust grains selected from Apollo 11 and 17 dust samples, and spherical silica particles by exposing them to mono-energetic electron beams in the 10-200 eV energy range. The dust charging process by electron impact involving the SEEs discussed is found to be a complex charging phenomenon with strong particle size dependence. The measurements indicate substantial differences between the polarity and magnitude of the dust charging rates of individual small-size dust grains, and the measurements and model properties of corresponding bulk materials. A more comprehensive plan of measurements of the charging properties of individual dust grains for developing a database for realistic models of dust charging in astrophysical and lunar environments is in progress.

  4. Thermally activated long range electron transport in living biofilms.

    PubMed

    Yates, Matthew D; Golden, Joel P; Roy, Jared; Strycharz-Glaven, Sarah M; Tsoi, Stanislav; Erickson, Jeffrey S; El-Naggar, Mohamed Y; Calabrese Barton, Scott; Tender, Leonard M

    2015-12-28

    Microbial biofilms grown utilizing electrodes as metabolic electron acceptors or donors are a new class of biomaterials with distinct electronic properties. Here we report that electron transport through living electrode-grown Geobacter sulfurreducens biofilms is a thermally activated process with incoherent redox conductivity. The temperature dependency of this process is consistent with electron-transfer reactions involving hemes of c-type cytochromes known to play important roles in G. sulfurreducens extracellular electron transport. While incoherent redox conductivity is ubiquitous in biological systems at molecular-length scales, it is unprecedented over distances it appears to occur through living G. sulfurreducens biofilms, which can exceed 100 microns in thickness. PMID:26611733

  5. Electrokinesis is a microbial behavior that requires extracellular electron transport

    SciTech Connect

    Harris, Howard W.; El-Naggar, Mohamed Y.; Bretschger, Orianna; Ward, Melissa J.; Romine, Margaret F.; Obraztsova, Anna; Nealson, Kenneth H.

    2010-01-05

    Shewanella species are widespread in nature, enjoying a cosmopolitan distribution in marine,freshwater, sedimentary and soil environments (1), and have attracted considerable attention in recent years because of their ability to reduce an extensive number of different electron 3 acceptors, including the solid (oxy)hydroxides of iron and manganese, such as Fe(OH)3 and MnO2, using one or more proposed mechanisms of extracellular electron transport (EET) (2, 3). The EET ability of Shewanella species is consistent with their ability to generate electric current in microbial fuel cells in the absence of exogenous electron shuttles (4). Various strategies of extracellular electron transfer have been proposed in metal-reducing microbes, including naturally-occurring (2) or biogenic (5-7) soluble mediators that ‘shuttle’ electrons from cells to acceptors, as well as direct transfer using multiheme cytochromes located on the cell exterior (8) and transfer via conductive nanowires (9-11). S. oneidensis MR-1 features several proteins that are involved with the transport of electrons to the exterior of the cell where they play an important role with regard to the reduction of solid electron acceptors such as metal oxides. These include two outer-membrane decaheme c-type cytochromes (MtrC and OmcA), a membrane spanning protein (MtrB), and two periplasmic multi-heme c-type cytochromes (MtrA and CymA). Deletion of the genes encoding any of these proteins leads to phenotypes that are greatly inhibited with regard to metal-oxide reduction and current production in microbial fuel cells (MFCs) (12, 13). The mutation of genes that code for proteins involved in the movement of cytochromes to the outer membrane also results in loss of metal-reducing phenotypes (13). The shewanellae are highly motile, by virtue of a single polar flagellum, and individual S. oneidensis MR-1 cells have been tracked swimming at speeds of up to, and sometimes over, 100 μm/sec, although the average

  6. Ultrafast electronic transport in low dimensional semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Choi, Hyunyong; Norris, Theodore B.; Faist, Jérôme; Capasso, Federico

    2009-02-01

    Ultrafast time-resolved pump-probe measurements are used to study low energy excitations and dynamics of electronic transport in various semiconductor nanostructures. In quantum cascade lasers, we observe ultrafast gain recovery dynamics due to electronic transport in the structures. In particular, the nature of electronic transport had been addressed by using ultrafast optical techniques. Sub-picosecond resonant tunneling injection from the quantum cascade laser injector ground state into the upper lasing state was found to be incoherent due to strong dephasing in the active subband. We also observed the strong coupling of the electronic transport to the intra-cavity photon density, which we term "photon-driven transport". Note that this invited paper reviews the details of our recent observations (H. Choi et al., Phys. Rev. Lett., 100, 167401, 2008 and H. Choi, et al., Appl. Phys. Lett. 92, 122114 (2008)).

  7. Kinetic theory of transport processes in partially ionized reactive plasma, II: Electron transport properties

    NASA Astrophysics Data System (ADS)

    Zhdanov, V. M.; Stepanenko, A. A.

    2016-11-01

    The previously obtained in (Zhdanov and Stepanenko, 2016) general transport equations for partially ionized reactive plasma are employed for analysis of electron transport properties in molecular and atomic plasmas. We account for both elastic and inelastic interaction channels of electrons with atoms and molecules of plasma and also the processes of electron impact ionization of neutral particles and three-body ion-electron recombination. The system of scalar transport equations for electrons is discussed and the expressions for non-equilibrium corrections to electron ionization and recombination rates and the diagonal part of the electron pressure tensor are derived. Special attention is paid to analysis of electron energy relaxation during collisions with plasma particles having internal degrees of freedom and the expression for the electron coefficient of inelastic energy losses is deduced. We also derive the expressions for electron vector and tensorial transport fluxes and the corresponding transport coefficients for partially ionized reactive plasma, which represent a generalization of the well-known results obtained by Devoto (1967). The results of numerical evaluation of contribution from electron inelastic collisions with neutral particles to electron transport properties are presented for a series of molecular and atomic gases.

  8. Four papers on transportation and the environment

    NASA Astrophysics Data System (ADS)

    Roth, Kevin Daniel

    The main essay of this thesis, found in the first chapter, examines how two policies that are a priori equivalent, fuel economy standards and feebates, interact differently with complementary policies that also attempt to improve fuel economy. To examine these interactions I build a general equilibrium model of the automobile market that allows manufacturers to trade off horsepower, weight, and fuel economy of vehicles along a production possibility frontier (PPF). I also estimate household demand for vehicles and miles for a simulation model that includes the used car and scrappage markets. This model allows me to simulate the interaction of a research and development policy that increases the PPF of domestic firms, or a tax credit that increases demand for efficient vehicles, with either a CAFE standard or feebate. I find that vehicle emissions increase under all these interactions but the effects are muted under the feebate because it allows fuel economy to improve by 0.60% to 1.88%, while CAFE, by targeting an average fuel economy, will always offset these uncoordinated complementary policies. The second essay examines transportation systems with unpriced congestion where single-occupant low-emission vehicles are allowed into high occupancy vehicle (HOV) lanes to encourage their adoption exacerbates congestion costs for carpoolers. The resulting welfare effects of the policy are negative, with environmental benefits overwhelmingly dominated by the increased congestion costs. Exploiting the introduction of the Clean Air Vehicle Stickers policy in California with a regression discontinuity design, our results imply a best-case cost of 124 per ton of reductions in greenhouse gases, 606,000 dollars per ton of nitrogen oxides reduction, and $505,000 dollars per ton of hydrocarbon reduction, exceeding those of other options readily available to policymakers. The third essay examines the 'Energy Paradox.' From previous literature, it can be found that consumers tend

  9. Spin transport in tilted electron vortex beams

    NASA Astrophysics Data System (ADS)

    Basu, Banasri; Chowdhury, Debashree

    2014-12-01

    In this paper we have enlightened the spin related issues of tilted Electron vortex beams. We have shown that in the skyrmionic model of electron we can have the spin Hall current considering the tilted type of electron vortex beam. We have considered the monopole charge of the tilted vortex as time dependent and through the time variation of the monopole charge we can explain the spin Hall effect of electron vortex beams. Besides, with an external magnetic field we can have a spin filter configuration.

  10. Spin transport in tilted electron vortex beams

    SciTech Connect

    Basu, Banasri; Chowdhury, Debashree

    2014-12-10

    In this paper we have enlightened the spin related issues of tilted Electron vortex beams. We have shown that in the skyrmionic model of electron we can have the spin Hall current considering the tilted type of electron vortex beam. We have considered the monopole charge of the tilted vortex as time dependent and through the time variation of the monopole charge we can explain the spin Hall effect of electron vortex beams. Besides, with an external magnetic field we can have a spin filter configuration.

  11. Tuning anisotropic electronic transport properties of phosphorene via substitutional doping.

    PubMed

    Guo, Caixia; Xia, Congxin; Fang, Lizhen; Wang, Tianxing; Liu, Yufang

    2016-10-01

    Using first-principles calculations, we studied the anisotropic electronic transport properties of pristine and X-doped phosphorene (X = B, Al, Ga, C, Si, Ge, N, As, O, S, and Se atoms). The results show that doping different elements can induce obviously different electronic transport characteristics. Moreover, isovalent doping maintains semiconducting characteristics and anisotropic transport properties, while group IV and VI atoms doping can induce metal properties. Meanwhile, Al and Ga substituting P decrease the anisotropic behaviors of transport, and other atom doping still preserves anisotropic characteristics. Interestingly, obvious negative differential resistance behaviors can be observed in C, Si, Ge, O, S, and Se-doped phosphorene.

  12. Terahertz electromodulation spectroscopy of electron transport in GaN

    SciTech Connect

    Engelbrecht, S. G.; Arend, T. R.; Kersting, R.; Zhu, T.; Kappers, M. J.

    2015-03-02

    Time-resolved terahertz (THz) electromodulation spectroscopy is applied to investigate the high-frequency transport of electrons in gallium nitride at different doping concentrations and densities of threading dislocations. At THz frequencies, all structures reveal Drude transport. The analysis of the spectral response provides the fundamental transport properties, such as the electron scattering time and the electrons' conductivity effective mass. We observe the expected impact of ionized-impurity scattering and that scattering at threading dislocations only marginally affects the high-frequency mobility.

  13. Non-nuclear electron transport channels in hollow molecules

    NASA Astrophysics Data System (ADS)

    Zhao, Jin; Petek, Hrvoje

    2014-08-01

    Electron transport in inorganic semiconductors and metals occurs through delocalized bands formed by overlapping electron orbitals. Strong correlation of electronic wave functions with the ionic cores couples the electron and lattice motions, leading to efficient interaction and scattering that degrades coherent charge transport. By contrast, unoccupied electronic states at energies near the vacuum level with diffuse molecular orbitals may form nearly-free-electron bands with density maxima in non-nuclear interstitial voids, which are subject to weaker electron-phonon interaction. The position of such bands typically above the frontier orbitals, however, renders them unstable with respect to electronic interband relaxation and therefore unsuitable for charge transport. Through electronic-structure calculations, we engineer stable, non-nuclear, nearly-free-electron conduction channels in low-dimensional molecular materials by tailoring their electrostatic and polarization potentials. We propose quantum structures of graphane-derived Janus molecular sheets with spatially isolated conducting and insulating regions that potentially exhibit emergent electronic properties, as a paradigm for molecular-scale non-nuclear charge conductors; we also describe tuning of their electronic properties by application of external fields and calculate their electron-acoustic-phonon interaction.

  14. Photosynthetic, respiratory and extracellular electron transport pathways in cyanobacteria.

    PubMed

    Lea-Smith, David J; Bombelli, Paolo; Vasudevan, Ravendran; Howe, Christopher J

    2016-03-01

    Cyanobacteria have evolved elaborate electron transport pathways to carry out photosynthesis and respiration, and to dissipate excess energy in order to limit cellular damage. Our understanding of the complexity of these systems and their role in allowing cyanobacteria to cope with varying environmental conditions is rapidly improving, but many questions remain. We summarize current knowledge of cyanobacterial electron transport pathways, including the possible roles of alternative pathways in photoprotection. We describe extracellular electron transport, which is as yet poorly understood. Biological photovoltaic devices, which measure electron output from cells, and which have been proposed as possible means of renewable energy generation, may be valuable tools in understanding cyanobacterial electron transfer pathways, and enhanced understanding of electron transfer may allow improvements in the efficiency of power output. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux.

  15. Photosynthetic, respiratory and extracellular electron transport pathways in cyanobacteria.

    PubMed

    Lea-Smith, David J; Bombelli, Paolo; Vasudevan, Ravendran; Howe, Christopher J

    2016-03-01

    Cyanobacteria have evolved elaborate electron transport pathways to carry out photosynthesis and respiration, and to dissipate excess energy in order to limit cellular damage. Our understanding of the complexity of these systems and their role in allowing cyanobacteria to cope with varying environmental conditions is rapidly improving, but many questions remain. We summarize current knowledge of cyanobacterial electron transport pathways, including the possible roles of alternative pathways in photoprotection. We describe extracellular electron transport, which is as yet poorly understood. Biological photovoltaic devices, which measure electron output from cells, and which have been proposed as possible means of renewable energy generation, may be valuable tools in understanding cyanobacterial electron transfer pathways, and enhanced understanding of electron transfer may allow improvements in the efficiency of power output. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux. PMID:26498190

  16. Large electron screening effect in different environments

    SciTech Connect

    Cvetinović, Aleksandra Lipoglavšek, Matej; Markelj, Sabina; Vesić, Jelena

    2015-10-15

    Electron screening effect was studied in the {sup 1}H({sup 7}Li,α){sup 4}He, {sup 1}H({sup 11}B,α){sup 4}He and {sup 1}H({sup 19}F,αγ){sup 16}O reactions in inverse kinematics on different hydrogen implanted targets. Results show large electron screening potentials strongly dependent on the proton number Z of the projectile.

  17. Ballistic electron transport in wrinkled superlattices

    NASA Astrophysics Data System (ADS)

    Mitran, T. L.; Nemnes, G. A.; Ion, L.; Dragoman, Daniela

    2016-07-01

    Inspired by the problem of elastic wave scattering on wrinkled interfaces, we studied the scattering of ballistic electrons on a wrinkled potential energy region. The electron transmission coefficient depends on both wrinkle amplitude and periodicity, having different behaviors for positive and negative scattering potential energies. For scattering on potential barriers, minibands appear in the electron transmission, as in superlattices, whereas for scattering on periodic potential wells the transmission coefficient has a more complex form. Besides suggesting that tuning of electron transmission is possible by modifying the scattering potential via voltages on wrinkled gate electrodes, our results emphasize the analogies between ballistic electrons and elastic waves even in scattering problems on non-typical configurations.

  18. Fast electron generation and transport in a turbulent, magnetized plasma

    SciTech Connect

    Stoneking, W.R.

    1994-05-01

    The nature of fast electron generation and transport in the Madison Symmetric Torus (MST) reversed field pinch (RFP) is investigated using two electron energy analyzer (EEA) probes and a thermocouple calorimeter. The parallel velocity distribution of the fast electron population is well fit by a drifted Maxwellian distribution with temperature of about 100 eV and drift velocity of about 2 {times} 10{sup 6} m/s. Cross-calibration of the EEA with the calorimeter provides a measurement of the fast electron perpendicular temperature of 30 eV, much lower than the parallel temperature, and is evidence that the kinetic dynamo mechanism (KDT) is not operative in MST. The fast electron current is found to match to the parallel current at the edge, and the fast electron density is about 4 {times} 10{sup 11} cm{sup {minus}3} independent of the ratio of the applied toroidal electric field to the critical electric field for runaways. First time measurements of magnetic fluctuation induced particle transport are reported. By correlating electron current fluctuations with radial magnetic fluctuations the transported flux of electrons is found to be negligible outside r/a{approximately}0.9, but rises the level of the expected total particle losses inside r/a{approximately}0.85. A comparison of the measured diffusion coefficient is made with the ausilinear stochastic diffusion coefficient. Evidence exists that the reduction of the transport is due to the presence of a radial ambipolar electric field of magnitude 500 V/m, that acts to equilibrate the ion and electron transport rates. The convective energy transport associated with the measured particle transport is large enough to account for the observed magnetic fluctuation induced energy transport in MST.

  19. Non-nuclear Electron Transport Channels in Hollow Molecules

    SciTech Connect

    Zhao, Jin; Petek, Hrvoje

    2014-08-15

    Electron transport in inorganic semiconductors and metals occurs through delocalized bands formed by overlapping electron orbitals. Strong correlation of electronic wave functions with the ionic cores couples the electron and lattice motions, leading to efficient interaction and scattering that degrades coherent charge transport. By contrast, unoccupied electronic states at energies near the vacuum level with diffuse molecular orbitals may form nearly-free-electron bands with density maxima in non-nuclear interstitial voids, which are subject to weaker electron-phonon interaction. The position of such bands typically above the frontier orbitals, however, renders them unstable with respect to electronic interband relaxation and therefore unsuitable for charge transport. Through electronic-structure calculations, we engineer stable, non-nuclear, nearly-free-electron conduction channels in low-dimensional molecular materials by tailoring their electrostatic and polarization potentials. We propose quantum structures of graphane-derived Janus molecular sheets with spatially isolated conducting and insulating regions that potentially exhibit emergent electronic properties, as a paradigm for molecular-scale non-nuclear charge conductors; we also describe tuning of their electronic properties by application of external fields and calculate their electron–acoustic-phonon interaction.

  20. Electronic transport and lasing in microstructures

    SciTech Connect

    Lax, M.

    1992-01-01

    We consider the interaction of hot carriers with hot phonons in a quantum well. Transport is considered in the transverse direction and tunneling through the well barriers. Time-dependent transport effects down to the femto-second regime are included, as are strong and/or microwave fields, with negative resistance effects. Resonant tunneling assisted by phonon relaxation and infra-red radiation will be explored. The limitations on transmission of information due to partition noise, as influenced by the design of semiconductor feedback lasers will be considered. The use of light scattering and decision theory to detect shell-like aerosols is examined.

  1. Persistence and transport potential of chemicals in a multimedia environment

    SciTech Connect

    van de Meent, D.; McKone, T.E.; Parkerton, T.; Matthies, M.; Scheringer, M.; Wania, F.; Purdy, R.; Bennett, D.H.

    2000-02-01

    Persistence in the environment and potential for long-range transport are related since time in the environment is required for transport. A persistent chemical will travel longer distances than a reactive chemical that shares similar chemical properties. Scheringer (1997) has demonstrated the correlation between persistence and transport distance for different organic chemicals. However, this correlation is not sufficiently robust to predict one property from the other. Specific chemicals that are persistent mayor may not exhibit long-range transport potential. Persistence and long-range transport also present different societal concerns. Persistence concerns relate to the undesired possibility that chemicals produced and used now may somehow negatively affect future generations. Long-range transport concerns relate to the undesired presence of chemicals in areas where these compounds have not been used. Environmental policy decisions can be based on either or both considerations depending on the aim of the regulatory program. In this chapter, definitions and methods for quantifying persistence and transport potential of organic chemicals are proposed which will assist in the development of sound regulatory frameworks.

  2. RHIC electron lens beam transport system design considerations

    SciTech Connect

    Gu, X.; Pikin, A.; Okamura, M.; Fischer, W.; Luo, Y.; Gupta, R.; Hock, J.; Jain, A.; Raparia, D.

    2010-10-01

    To apply head-on beam-beam compensation for RHIC, two electron lenses are designed and will be installed at IP10. Electron beam transport system is one of important subsystem, which is used to transport electron beam from electron gun side to collector side. This system should be able to change beam size inside superconducting magnet and control beam position with 5 mm in horizontal and vertical plane. Some other design considerations for this beam transport system are also reported in this paper. The head-on beam-beam effect is one of important nonlinear source in storage ring and linear colliders, which have limited the luminosity improvement of many colliders, such as SppS, Tevatron and RHIC. In order to enhance the performance of colliders, beam-beam effects can be compensated with direct space charge compensation, indirect space charge compensation or betatron phase cancellation scheme. Like other colliders, indirect space charge compensation scheme (Electron Lens) was also proposed for Relativistic Heavy Ion Collider (RHIC) beam-beam compensation at Brookhaven National Laboratory. The two similar electron lenses are located in IR10 between the DX magnets. One RHIC electron lens consists of one DC electron gun, one superconducting magnet, one electron collector and beam transport system.

  3. Energy-filtered cold electron transport at room temperature

    PubMed Central

    Bhadrachalam, Pradeep; Subramanian, Ramkumar; Ray, Vishva; Ma, Liang-Chieh; Wang, Weichao; Kim, Jiyoung; Cho, Kyeongjae; Koh, Seong Jin

    2014-01-01

    Fermi-Dirac electron thermal excitation is an intrinsic phenomenon that limits functionality of various electron systems. Efforts to manipulate electron thermal excitation have been successful when the entire system is cooled to cryogenic temperatures, typically <1 K. Here we show that electron thermal excitation can be effectively suppressed at room temperature, and energy-suppressed electrons, whose energy distribution corresponds to an effective electron temperature of ~45 K, can be transported throughout device components without external cooling. This is accomplished using a discrete level of a quantum well, which filters out thermally excited electrons and permits only energy-suppressed electrons to participate in electron transport. The quantum well (~2 nm of Cr2O3) is formed between source (Cr) and tunnelling barrier (SiO2) in a double-barrier-tunnelling-junction structure having a quantum dot as the central island. Cold electron transport is detected from extremely narrow differential conductance peaks in electron tunnelling through CdSe quantum dots, with full widths at half maximum of only ~15 mV at room temperature. PMID:25204839

  4. Computer modeling of electron and proton transport in chloroplasts.

    PubMed

    Tikhonov, Alexander N; Vershubskii, Alexey V

    2014-07-01

    Photosynthesis is one of the most important biological processes in biosphere, which provides production of organic substances from atmospheric CO2 and water at expense of solar energy. In this review, we contemplate computer models of oxygenic photosynthesis in the context of feedback regulation of photosynthetic electron transport in chloroplasts, the energy-transducing organelles of the plant cell. We start with a brief overview of electron and proton transport processes in chloroplasts coupled to ATP synthesis and consider basic regulatory mechanisms of oxygenic photosynthesis. General approaches to computer simulation of photosynthetic processes are considered, including the random walk models of plastoquinone diffusion in thylakoid membranes and deterministic approach to modeling electron transport in chloroplasts based on the mass action law. Then we focus on a kinetic model of oxygenic photosynthesis that includes key stages of the linear electron transport, alternative pathways of electron transfer around photosystem I (PSI), transmembrane proton transport and ATP synthesis in chloroplasts. This model includes different regulatory processes: pH-dependent control of the intersystem electron transport, down-regulation of photosystem II (PSII) activity (non-photochemical quenching), the light-induced activation of the Bassham-Benson-Calvin (BBC) cycle. The model correctly describes pH-dependent feedback control of electron transport in chloroplasts and adequately reproduces a variety of experimental data on induction events observed under different experimental conditions in intact chloroplasts (variations of CO2 and O2 concentrations in atmosphere), including a complex kinetics of P700 (primary electron donor in PSI) photooxidation, CO2 consumption in the BBC cycle, and photorespiration. Finally, we describe diffusion-controlled photosynthetic processes in chloroplasts within the framework of the model that takes into account complex architecture of

  5. Electron transport in one-dimensional plasmas

    SciTech Connect

    Wienke, B.R.

    1983-11-01

    A one-dimensional, multigroup, discrete ordinates technique for computing electron energy deposition in plasmas is detailed. The Fokker-Planck collision operator is employed in the continuous approximation and electric fields (considered external) are included in the equation. Bremsstrahlung processes are not treated. Comparisons with analytic and Monte Carlo results are given. Fits to deposition profiles and energy scaling are proposed and discussed for monoenergetic and Maxwellian sources in the range, 0 to 150 keV, with and without uniform fields. The techniques employed to track electrons are generally useful in situations where the background plasma temperature is an order of magnitude smaller than the electron energy and collective plasma effects are negligible. We have used the approach successfully in laser pellet implosion applications.

  6. Conditioner for a helically transported electron beam

    SciTech Connect

    Wang, C.

    1992-05-01

    The kinetic theory is developed to investigate a conditioner for a helically imported electron beam. Linear expressions for axial velocity spread are derived. Numerical simulation is used to check the theoretical results and examine nonlinear aspects of the conditioning process. The results show that in the linear regime the action of the beam conditioner on a pulsed beam mainly depends on the phase at which the beam enters the conditioner and depends only slightly on the operating wavelength. In the nonlinear regime, however, the action of the conditioner strongly depends on the operating wavelength and only slightly upon the entrance phase. For a properly chosen operating wavelength, a little less than the electron`s relativistic cyclotron wavelength, the conditioner can decrease the axial velocity spread of a pulsed beam down to less than one-third of its initial value.

  7. A model environment for outer zone electrons

    NASA Technical Reports Server (NTRS)

    Singley, G. W.; Vette, J. I.

    1972-01-01

    A brief morphology of outer zone electrons is given to illustrate the nature of the phenomena that we are attempting to model. This is followed by a discussion of the data processing that was done with the various data received from the experimenters before incorporating it into the data base from which this model was ultimately derived. The details of the derivation are given, and several comparisons of the final model with the various experimental measurements are presented.

  8. Coherent electron transport in a helical nanotube

    NASA Astrophysics Data System (ADS)

    Liang, Guo-Hua; Wang, Yong-Long; Du, Long; Jiang, Hua; Kang, Guang-Zhen; Zong, Hong-Shi

    2016-09-01

    The quantum dynamics of carriers bound to helical tube surfaces is investigated in a thin-layer quantization scheme. By numerically solving the open-boundary Schrödinger equation in curvilinear coordinates, geometric effect on the coherent transmission spectra is analysed in the case of single propagating mode as well as multimode. It is shown that, the coiling endows the helical nanotube with different transport properties from a bent cylindrical surface. Fano resonance appears as a purely geometric effect in the conductance, the corresponding energy of quasibound state is obviously influenced by the torsion and length of the nanotube. We also find new plateaus in the conductance. The transport of double-degenerate mode in this geometry is reminiscent of the Zeeman coupling between the magnetic field and spin angular momentum in quasi-one-dimensional structure.

  9. Neoclassical electron transport in tokamaks with neutral-beam injection

    SciTech Connect

    Helander, P.; Akers, R.J.

    2005-04-15

    The collisional interaction between neutral-beam ions and bulk plasma electrons leads to convective transport of particles and energy similar to the well-known Ware pinch. These transport fluxes are calculated, and it is found that the particle flux is outward when the neutral beams are in the same direction as the plasma current and inward otherwise, while the opposite holds for the electron heat transport. This effectively shifts the neutral-beam fueling profile approximately one fast-ion banana width outward during coinjection and inward during counterinjection, and could help to explain why very different plasma behavior is sometimes observed when the direction of the plasma current is reversed.

  10. Transport of secondary electrons and reactive species in ion tracks

    NASA Astrophysics Data System (ADS)

    Surdutovich, Eugene; Solov'yov, Andrey V.

    2015-08-01

    The transport of reactive species brought about by ions traversing tissue-like medium is analysed analytically. Secondary electrons ejected by ions are capable of ionizing other molecules; the transport of these generations of electrons is studied using the random walk approximation until these electrons remain ballistic. Then, the distribution of solvated electrons produced as a result of interaction of low-energy electrons with water molecules is obtained. The radial distribution of energy loss by ions and secondary electrons to the medium yields the initial radial dose distribution, which can be used as initial conditions for the predicted shock waves. The formation, diffusion, and chemical evolution of hydroxyl radicals in liquid water are studied as well. COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy.

  11. Catalytic photoinduced electron transport across a lipid bilayer mediated by a membrane-soluble electron relay.

    PubMed

    Limburg, B; Bouwman, E; Bonnet, S

    2015-12-14

    Unidirectional photocatalytic electron transfer from a hydrophilic electron donor encapsulated in the interior of a liposome, to a hydrophilic electron acceptor on the other side of the membrane, has been achieved using the simple membrane-soluble electron relay 1-methoxy-N-methylphenazinium (MMP(+)). The total amount of photoproduct (>140 nmol) exceeds the number of moles of MMP(+) present (125 nmol), thus showing that the transport of electrons is catalytic.

  12. Electron Trapping and Charge Transport by Large Amplitude Whistlers

    NASA Technical Reports Server (NTRS)

    Kellogg, P. J.; Cattell, C. A.; Goetz, K.; Monson, S. J.; Wilson, L. B., III

    2010-01-01

    Trapping of electrons by magnetospheric whistlers is investigated using data from the Waves experiment on Wind and the S/WAVES experiment on STEREO. Waveforms often show a characteristic distortion which is shown to be due to electrons trapped in the potential of the electrostatic part of oblique whistlers. The density of trapped electrons is significant, comparable to that of the unperturbed whistler. Transport of these trapped electrons to new regions can generate potentials of several kilovolts, Trapping and the associated potentials may play an important role in the acceleration of Earth's radiation belt electrons.

  13. Electron transport through nuclear pasta in magnetized neutron stars

    NASA Astrophysics Data System (ADS)

    Yakovlev, D. G.

    2015-10-01

    We present a simple model for electron transport in a possible layer of exotic nuclear clusters (in the so-called nuclear pasta layer) between the crust and liquid core of a strongly magnetized neutron star. The electron transport there can be strongly anisotropic and gyrotropic. The anisotropy is produced by different electron effective collision frequencies along and across local symmetry axis in domains of exotic ordered nuclear clusters and by complicated effects of the magnetic field. We also calculate averaged kinetic coefficients in case local domains are freely oriented. Possible applications of the obtained results and open problems are outlined.

  14. Treating electron transport in MCNP{sup trademark}

    SciTech Connect

    Hughes, H.G.

    1996-12-31

    The transport of electrons and other charged particles is fundamentally different from that of neutrons and photons. A neutron, in aluminum slowing down from 0.5 MeV to 0.0625 MeV will have about 30 collisions; a photon will have fewer than ten. An electron with the same energy loss will undergo 10{sup 5} individual interactions. This great increase in computational complexity makes a single- collision Monte Carlo approach to electron transport unfeasible for many situations of practical interest. Considerable theoretical work has been done to develop a variety of analytic and semi-analytic multiple-scattering theories for the transport of charged particles. The theories used in the algorithms in MCNP are the Goudsmit-Saunderson theory for angular deflections, the Landau an theory of energy-loss fluctuations, and the Blunck-Leisegang enhancements of the Landau theory. In order to follow an electron through a significant energy loss, it is necessary to break the electron`s path into many steps. These steps are chosen to be long enough to encompass many collisions (so that multiple-scattering theories are valid) but short enough that the mean energy loss in any one step is small (for the approximations in the multiple-scattering theories). The energy loss and angular deflection of the electron during each step can then be sampled from probability distributions based on the appropriate multiple- scattering theories. This subsumption of the effects of many individual collisions into single steps that are sampled probabilistically constitutes the ``condensed history`` Monte Carlo method. This method is exemplified in the ETRAN series of electron/photon transport codes. The ETRAN codes are also the basis for the Integrated TIGER Series, a system of general-purpose, application-oriented electron/photon transport codes. The electron physics in MCNP is similar to that of the Integrated TIGER Series.

  15. Theoretical study of particle transport in electron internal transport barriers in TCV

    SciTech Connect

    Fable, E.; Sauter, O.; Marinoni, A.; Zucca, C.

    2006-11-30

    Previous results from the analysis of fully non inductively sustained electron internal transport barriers (eITBs) in TCV show that a strong coupling exists between electron temperature and density profiles inside the barrier. A phenomenology that is completely different from the standard L-mode is observed . New experimental results assess transient phases to calculate particle convection and diffusion coefficients, allowing also to discuss the role of neoclassical transport. Gyrokinetic and gyrofluid analysis of steady-state eITBs provide tools to understand the mechanism that drive the observed density peaking in advanced scenarios with internal transport barriers and dominant electron heating.

  16. Electronic transport in ultranarrow zigzag graphene nanoribbons with edge disorders

    NASA Astrophysics Data System (ADS)

    Liu, Y. L.; Xu, G. L.; Zhang, X. W.

    2016-11-01

    We investigate the transport properties of ultranarrow zigzag graphene nanoribbons (ZGNRs) with edge vacancies by using recursive Green's function method. Transport gaps are observed when the vacancies are distributed uniformly on both sides. In addition, ZGNRs with symmetrical structure have much larger transport gaps than the asymmetrical ones. This phenomenon results from the different band structures between them. We also calculate the conductance of ZGNRs with edge vacancies distributed randomly. It shows that transport gaps decrease exponentially with the increasing of ZGNRs width because the symmetry of structure is broken by the random edge vacancies. Localization analysis reveals that the electronic transport channels around Fermi energy are blockaded so that they are not responsible for electron transmission.

  17. Study of electron transport in hydrocarbon gases

    NASA Astrophysics Data System (ADS)

    Hasegawa, H.; Date, H.

    2015-04-01

    The drift velocity and the effective ionization coefficient of electrons in the organic gases, C2H2, C2H4, C2H6, CH3OH, C2H5OH, C6H6, and C6H5CH3, have been measured over relatively wide ranges of density-reduced electric fields (E/N) at room temperature (around 300 K). The drift velocity was measured, based on the arrival-time spectra of electrons by using a double-shutter drift tube over the E/N range from 300 to 2800 Td, and the effective ionization coefficient (α - η) was determined by the steady-state Townsend method from 150 to 3000 Td. Whenever possible, these parameters were compared with those available in the literature. It has been shown that the swarm parameters for these gases have specific tendencies, depending on their molecular configurations.

  18. Conditioner for a helically transported electron beam

    SciTech Connect

    Wang, C.

    1992-05-01

    The kinetic theory is developed to investigate a conditioner for a helically imported electron beam. Linear expressions for axial velocity spread are derived. Numerical simulation is used to check the theoretical results and examine nonlinear aspects of the conditioning process. The results show that in the linear regime the action of the beam conditioner on a pulsed beam mainly depends on the phase at which the beam enters the conditioner and depends only slightly on the operating wavelength. In the nonlinear regime, however, the action of the conditioner strongly depends on the operating wavelength and only slightly upon the entrance phase. For a properly chosen operating wavelength, a little less than the electron's relativistic cyclotron wavelength, the conditioner can decrease the axial velocity spread of a pulsed beam down to less than one-third of its initial value.

  19. Surface excitations in the modelling of electron transport for electron-beam-induced deposition experiments

    PubMed Central

    Valentí, Roser; Werner, Wolfgang S

    2015-01-01

    Summary The aim of the present overview article is to raise awareness of an essential aspect that is usually not accounted for in the modelling of electron transport for focused-electron-beam-induced deposition (FEBID) of nanostructures: Surface excitations are on the one hand responsible for a sizeable fraction of the intensity in reflection-electron-energy-loss spectra for primary electron energies of up to a few kiloelectronvolts and, on the other hand, they play a key role in the emission of secondary electrons from solids, regardless of the primary energy. In this overview work we present a general perspective of recent works on the subject of surface excitations and on low-energy electron transport, highlighting the most relevant aspects for the modelling of electron transport in FEBID simulations. PMID:26171301

  20. Transport and Non-Invasive Position Detection of Electron Beams from Laser-Plasma Accelerators

    SciTech Connect

    Osterhoff, Jens; Sokollik, Thomas; Nakamura, Kei; Bakeman, Michael; Weingartner, R; Gonsalves, Anthony; Shiraishi, Satomi; Lin, Chen; vanTilborg, Jeroen; Geddes, Cameron; Schroeder, Carl; Esarey, Eric; Toth, Csaba; DeSantis, Stefano; Byrd, John; Gruner, F; Leemans, Wim

    2011-07-20

    The controlled imaging and transport of ultra-relativistic electrons from laser-plasma accelerators is of crucial importance to further use of these beams, e.g. in high peak-brightness light sources. We present our plans to realize beam transport with miniature permanent quadrupole magnets from the electron source through our THUNDER undulator. Simulation results demonstrate the importance of beam imaging by investigating the generated XUV-photon flux. In addition, first experimental findings of utilizing cavity-based monitors for non-invasive beam-position measurements in a noisy electromagnetic laser-plasma environment are discussed.

  1. Study of electron transport in hydrocarbon gases

    SciTech Connect

    Hasegawa, H.; Date, H.

    2015-04-07

    The drift velocity and the effective ionization coefficient of electrons in the organic gases, C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, C{sub 2}H{sub 6}, CH{sub 3}OH, C{sub 2}H{sub 5}OH, C{sub 6}H{sub 6}, and C{sub 6}H{sub 5}CH{sub 3}, have been measured over relatively wide ranges of density-reduced electric fields (E/N) at room temperature (around 300 K). The drift velocity was measured, based on the arrival-time spectra of electrons by using a double-shutter drift tube over the E/N range from 300 to 2800 Td, and the effective ionization coefficient (α − η) was determined by the steady-state Townsend method from 150 to 3000 Td. Whenever possible, these parameters were compared with those available in the literature. It has been shown that the swarm parameters for these gases have specific tendencies, depending on their molecular configurations.

  2. Evidence for global electron transportation into the jovian inner magnetosphere.

    PubMed

    Yoshioka, K; Murakami, G; Yamazaki, A; Tsuchiya, F; Kimura, T; Kagitani, M; Sakanoi, T; Uemizu, K; Kasaba, Y; Yoshikawa, I; Fujimoto, M

    2014-09-26

    Jupiter's magnetosphere is a strong particle accelerator that contains ultrarelativistic electrons in its inner part. They are thought to be accelerated by whistler-mode waves excited by anisotropic hot electrons (>10 kiloelectron volts) injected from the outer magnetosphere. However, electron transportation in the inner magnetosphere is not well understood. By analyzing the extreme ultraviolet line emission from the inner magnetosphere, we show evidence for global inward transport of flux tubes containing hot plasma. High-spectral-resolution scanning observations of the Io plasma torus in the inner magnetosphere enable us to generate radial profiles of the hot electron fraction. It gradually decreases with decreasing radial distance, despite the short collisional time scale that should thermalize them rapidly. This indicates a fast and continuous resupply of hot electrons responsible for exciting the whistler-mode waves.

  3. Evidence for global electron transportation into the jovian inner magnetosphere.

    PubMed

    Yoshioka, K; Murakami, G; Yamazaki, A; Tsuchiya, F; Kimura, T; Kagitani, M; Sakanoi, T; Uemizu, K; Kasaba, Y; Yoshikawa, I; Fujimoto, M

    2014-09-26

    Jupiter's magnetosphere is a strong particle accelerator that contains ultrarelativistic electrons in its inner part. They are thought to be accelerated by whistler-mode waves excited by anisotropic hot electrons (>10 kiloelectron volts) injected from the outer magnetosphere. However, electron transportation in the inner magnetosphere is not well understood. By analyzing the extreme ultraviolet line emission from the inner magnetosphere, we show evidence for global inward transport of flux tubes containing hot plasma. High-spectral-resolution scanning observations of the Io plasma torus in the inner magnetosphere enable us to generate radial profiles of the hot electron fraction. It gradually decreases with decreasing radial distance, despite the short collisional time scale that should thermalize them rapidly. This indicates a fast and continuous resupply of hot electrons responsible for exciting the whistler-mode waves. PMID:25258073

  4. Evidence for global electron transportation into the jovian inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Yoshioka, K.; Murakami, G.; Yamazaki, A.; Tsuchiya, F.; Kimura, T.; Kagitani, M.; Sakanoi, T.; Uemizu, K.; Kasaba, Y.; Yoshikawa, I.; Fujimoto, M.

    2014-09-01

    Jupiter’s magnetosphere is a strong particle accelerator that contains ultrarelativistic electrons in its inner part. They are thought to be accelerated by whistler-mode waves excited by anisotropic hot electrons (>10 kiloelectron volts) injected from the outer magnetosphere. However, electron transportation in the inner magnetosphere is not well understood. By analyzing the extreme ultraviolet line emission from the inner magnetosphere, we show evidence for global inward transport of flux tubes containing hot plasma. High-spectral-resolution scanning observations of the Io plasma torus in the inner magnetosphere enable us to generate radial profiles of the hot electron fraction. It gradually decreases with decreasing radial distance, despite the short collisional time scale that should thermalize them rapidly. This indicates a fast and continuous resupply of hot electrons responsible for exciting the whistler-mode waves.

  5. The Changing Information Needs of Users in Electronic Information Environments.

    ERIC Educational Resources Information Center

    Kebede, Gashaw

    2002-01-01

    Focuses on the information needs of users that are changing as a results of changes in the availability of information content in electronic form. Highlights the trend and nature of the physical form in which information content is currently being made available for users' access and use in electronic information environments. (Author/LRW)

  6. Advanced Engineering Environments for Space Transportation System Development

    NASA Technical Reports Server (NTRS)

    Thomas, L. Dale; Smith, Charles A.; Beveridge, James

    2000-01-01

    There are significant challenges facing today's launch vehicle industry. Global competition, more complex products, geographically-distributed design teams, demands for lower cost, higher reliability and safer vehicles, and the need to incorporate the latest technologies quicker, all face the developer of a space transportation system. Within NASA, multiple technology development and demonstration projects are underway toward the objectives of safe, reliable, and affordable access to space. New information technologies offer promising opportunities to develop advanced engineering environments to meet these challenges. Significant advances in the state-of-the-art of aerospace engineering practice are envisioned in the areas of engineering design and analytical tools, cost and risk tools, collaborative engineering, and high-fidelity simulations early in the development cycle. At the Marshall Space Flight Center, work has begun on development of an advanced engineering environment specifically to support the design, modeling, and analysis of space transportation systems. This paper will give an overview of the challenges of developing space transportation systems in today's environment and subsequently discuss the advanced engineering environment and its anticipated benefits.

  7. 77 FR 38709 - Surface Transportation Environment and Planning Cooperative Research Program (STEP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ... Federal Highway Administration Surface Transportation Environment and Planning Cooperative Research...-LU) established the Surface Transportation Environment and Planning Cooperative Research Program... research on issues related to planning, environment, and realty will be included in future...

  8. 76 FR 50312 - Surface Transportation Environment and Planning Cooperative Research Program (STEP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-12

    ... Federal Highway Administration Surface Transportation Environment and Planning Cooperative Research...-LU) established the Surface Transportation Environment and Planning Cooperative Research Program... research on issues related to planning, environment, and realty will be included in future...

  9. 75 FR 38605 - Surface Transportation Environment and Planning Cooperative Research Program (STEP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... Federal Highway Administration Surface Transportation Environment and Planning Cooperative Research...-LU) established the Surface Transportation Environment and Planning Cooperative Research Program... research on issues related to planning, environment, and realty will be included in future...

  10. Dissipationless electron transport in photon-dressed nanostructures.

    PubMed

    Kibis, O V

    2011-09-01

    It is shown that the electron coupling to photons in field-dressed nanostructures can result in the ground electron-photon state with a nonzero electric current. Since the current is associated with the ground state, it flows without the Joule heating of the nanostructure and is nondissipative. Such a dissipationless electron transport can be realized in strongly coupled electron-photon systems with the broken time-reversal symmetry--particularly, in quantum rings and chiral nanostructures dressed by circularly polarized photons. PMID:21981519

  11. Electron Beam Freeform Fabrication in the Space Environment

    NASA Technical Reports Server (NTRS)

    Hafley, Robert A.; Taminger, Karen M. B.; Bird, R. Keith

    2007-01-01

    The influence of reduced gravitational forces (in space and on the lunar or Martian surfaces) on manufacturing processes must be understood for effective fabrication and repair of structures and replacement parts during long duration space missions. The electron beam freeform fabrication (EBF3) process uses an electron beam and wire to fabricate metallic structures. The process efficiencies of the electron beam and the solid wire feedstock make the EBF3 process attractive for use in-space. This paper will describe the suitability of the EBF3 process in the space environment and will highlight preliminary testing of the EBF3 process in a zero-gravity environment.

  12. Effect of dephasing on DNA sequencing via transverse electronic transport

    SciTech Connect

    Zwolak, Michael; Krems, Matt; Pershin, Yuriy V; Di Ventra, Massimiliano

    2009-01-01

    We study theoretically the effects of dephasing on DNA sequencing in a nanopore via transverse electronic transport. To do this, we couple classical molecular dynamics simulations with transport calculations using scattering theory. Previous studies, which did not include dephasing, have shown that by measuring the transverse current of a particular base multiple times, one can get distributions of currents for each base that are distinguishable. We introduce a dephasing parameter into transport calculations to simulate the effects of the ions and other fluctuations. These effects lower the overall magnitude of the current, but have little effect on the current distributions themselves. The results of this work further implicate that distinguishing DNA bases via transverse electronic transport has potential as a sequencing tool.

  13. Status of electron transport in MCNP{trademark}

    SciTech Connect

    Hughes, H.G.

    1997-10-01

    The latest version of MCNP, the Los Alamos Monte Carlo transport code, has now been officially released. A variety of new features are available in MCNP4B. Among these are differential operator perturbations, cross section plotting capabilities, enhanced diagnostics for transport in repeated structures and lattices, improved efficiency in distributed memory multiprocessing, corrected particle lifetime and lifespan estimators, and expanded software quality assurance procedures and testing, including testing of the multigroup Boltzmann Fokker Planck capability. New and improved cross section sets in the form of ENDF/B-VI evaluations have also been recently released and can be used in MCNP4B. Perhaps most significant for the interests of this special session, the electron transport algorithm has been improved, especially in the collisional energy loss straggling and the angular deflection treatments. In this paper, I shall concentrate on a fairly complete documentation of the current status of the electron transport methods in MCNP.

  14. Electron-Transport Properties of Few-Layer Black Phosphorus.

    PubMed

    Xu, Yuehua; Dai, Jun; Zeng, Xiao Cheng

    2015-06-01

    We perform the first-principles computational study of the effect of number of stacking layers and stacking style of the few-layer black phosphorus (BPs) on the electronic properties, including transport gap, current-voltage (i-v) relation, and differential conductance. Our computation is based on the nonequilibrium Green's function approach combined with density functional theory calculations. Specifically, we compute electron-transport properties of monolayer BP, bilayer BP, and trilayer BP as well as bilayer BPs with AB-, AA-, or AC-stacking. We find that the stacking number has greater influence on the transport gap than the stacking type. Conversely, the stacking type has greater influence on i-v curve and differential conductance than on the transport gap. This study offers useful guidance for determining the number of stacking layers and the stacking style of few-layer BP sheets in future experimental measurements and for potential applications in nanoelectronic devices.

  15. Mitochondrial ROS Produced via Reverse Electron Transport Extend Animal Lifespan

    PubMed Central

    Scialò, Filippo; Sriram, Ashwin; Fernández-Ayala, Daniel; Gubina, Nina; Lõhmus, Madis; Nelson, Glyn; Logan, Angela; Cooper, Helen M.; Navas, Plácido; Enríquez, Jose Antonio; Murphy, Michael P.; Sanz, Alberto

    2016-01-01

    Summary Increased production of reactive oxygen species (ROS) has long been considered a cause of aging. However, recent studies have implicated ROS as essential secondary messengers. Here we show that the site of ROS production significantly contributes to their apparent dual nature. We report that ROS increase with age as mitochondrial function deteriorates. However, we also demonstrate that increasing ROS production specifically through respiratory complex I reverse electron transport extends Drosophila lifespan. Reverse electron transport rescued pathogenesis induced by severe oxidative stress, highlighting the importance of the site of ROS production in signaling. Furthermore, preventing ubiquinone reduction, through knockdown of PINK1, shortens lifespan and accelerates aging; phenotypes that are rescued by increasing reverse electron transport. These results illustrate that the source of a ROS signal is vital in determining its effects on cellular physiology and establish that manipulation of ubiquinone redox state is a valid strategy to delay aging. PMID:27076081

  16. Mitochondrial ROS Produced via Reverse Electron Transport Extend Animal Lifespan.

    PubMed

    Scialò, Filippo; Sriram, Ashwin; Fernández-Ayala, Daniel; Gubina, Nina; Lõhmus, Madis; Nelson, Glyn; Logan, Angela; Cooper, Helen M; Navas, Plácido; Enríquez, Jose Antonio; Murphy, Michael P; Sanz, Alberto

    2016-04-12

    Increased production of reactive oxygen species (ROS) has long been considered a cause of aging. However, recent studies have implicated ROS as essential secondary messengers. Here we show that the site of ROS production significantly contributes to their apparent dual nature. We report that ROS increase with age as mitochondrial function deteriorates. However, we also demonstrate that increasing ROS production specifically through respiratory complex I reverse electron transport extends Drosophila lifespan. Reverse electron transport rescued pathogenesis induced by severe oxidative stress, highlighting the importance of the site of ROS production in signaling. Furthermore, preventing ubiquinone reduction, through knockdown of PINK1, shortens lifespan and accelerates aging; phenotypes that are rescued by increasing reverse electron transport. These results illustrate that the source of a ROS signal is vital in determining its effects on cellular physiology and establish that manipulation of ubiquinone redox state is a valid strategy to delay aging.

  17. Progress in Simulating Turbulent Electron Thermal Transport in NSTX

    SciTech Connect

    Guttenfelder, Walter; Kaye, S. M.; Ren, Y.; Bell, R. E.; Hammett, G. W.; LeBlanc, B. P.; Mikkelsen, D. R.; Peterson, J. L.; Nevins, W. M.; Candy, J.; Yuh, H.

    2013-07-17

    Nonlinear simulations based on multiple NSTX discharge scenarios have progressed to help differentiate unique instability mechanisms and to validate with experimental turbulence and transport data. First nonlinear gyrokinetic simulations of microtearing (MT) turbulence in a high-beta NSTX H-mode discharge predict experimental levels of electron thermal transport that are dominated by magnetic flutter and increase with collisionality, roughly consistent with energy confinement times in dimensionless collisionality scaling experiments. Electron temperature gradient (ETG) simulations predict significant electron thermal transport in some low and high beta discharges when ion scales are suppressed by E x B shear. Although the predicted transport in H-modes is insensitive to variation in collisionality (inconsistent with confinement scaling), it is sensitive to variations in other parameters, particularly density gradient stabilization. In reversed shear (RS) Lmode discharges that exhibit electron internal transport barriers, ETG transport has also been shown to be suppressed nonlinearly by strong negative magnetic shear, s<<0. In many high beta plasmas, instabilities which exhibit a stiff beta dependence characteristic of kinetic ballooning modes (KBM) are sometimes found in the core region. However, they do not have a distinct finite beta threshold, instead transitioning gradually to a trapped electron mode (TEM) as beta is reduced to zero. Nonlinear simulations of this "hybrid" TEM/KBM predict significant transport in all channels, with substantial contributions from compressional magnetic perturbations. As multiple instabilities are often unstable simultaneously in the same plasma discharge, even on the same flux surface, unique parametric dependencies are discussed which may be useful for distinguishing the different mechanisms experimentally.

  18. Coherently driven, ultrafast electron-phonon dynamics in transport junctions

    SciTech Connect

    Szekely, Joshua E.; Seideman, Tamar

    2014-07-28

    Although the vast majority of studies of transport via molecular-scale heterojunctions have been conducted in the (static) energy domain, experiments are currently beginning to apply time domain approaches to the nanoscale transport problem, combining spatial with temporal resolution. It is thus an opportune time for theory to develop models to explore both new phenomena in, and new potential applications of, time-domain, coherently driven molecular electronics. In this work, we study the interaction of a molecular phonon with an electronic wavepacket transmitted via a conductance junction within a time-domain model that treats the electron and phonon on equal footing and spans the weak to strong electron-phonon coupling strengths. We explore interference between two coherent energy pathways in the electronic subspace, thus complementing previous studies of coherent phenomena in conduction junctions, where the stationary framework was used to study interference between spatial pathways. Our model provides new insights into phase decoherence and population relaxation within the electronic subspace, which have been conventionally treated by density matrix approaches that often rely on phenomenological parameters. Although the specific case of a transport junction is explored, our results are general, applying also to other instances of coupled electron-phonon systems.

  19. Transport Properties of III-N Hot Electron Transistors

    NASA Astrophysics Data System (ADS)

    Suntrup, Donald J., III

    Unipolar hot electron transistors (HETs) represent a tantalizing alternative to established bipolar transistor technologies. During device operation electrons are injected over a large emitter barrier into the base where they travel along the device axis with very high velocity. Upon arrival at the collector barrier, high-energy electrons pass over the barrier and contribute to collector current while low-energy electrons are quantum mechanically reflected back into the base. Designing the base with thickness equal to or less than the hot electron mean free path serves to minimize scattering events and thus enable quasi-ballistic operation. Large current gain is achieved by increasing the ratio of transmitted to reflected electrons. Although III-N HETs have undergone substantial development in recent years, there remain ample opportunities to improve key device metrics. In order to engineer improved device performance, a deeper understanding of the operative transport physics is needed. Fortunately, the HET provides fertile ground for studying several prominent electron transport phenomena. In this thesis we present results from several studies that use the III-N HET as both emitter and analyzer of hot electron momentum states. The first provides a measurement of the hot electron mean free path and the momentum relaxation rate in GaN; the second relies on a new technique called electron injection spectroscopy to investigate the effects of barrier height inhomogeneity in the emitter. To supplement our analysis we develop a comprehensive theory of coherent electron transport that allows us to model the transfer characteristics of complex heterojunctions. Such a model provides a theoretical touchstone with which to compare our experimental results. While these studies are of potential interest in their own right, we interpret the results with an eye toward improving next-generation device performance.

  20. Simulation of electron transport in quantum well devices

    NASA Technical Reports Server (NTRS)

    Miller, D. R.; Gullapalli, K. K.; Reddy, V. R.; Neikirk, D. P.

    1992-01-01

    Double barrier resonant tunneling diodes (DBRTD) have received much attention as possible terahertz devices. Despite impressive experimental results, the specifics of the device physics (i.e., how the electrons propagate through the structure) are only qualitatively understood. Therefore, better transport models are warranted if this technology is to mature. In this paper, the Lattice Wigner function is used to explain the important transport issues associated with DBRTD device behavior.

  1. Anomalous electronic transport in dual-nanostructured lead telluride.

    PubMed

    He, J Q; Sootsman, J R; Xu, L Q; Girard, S N; Zheng, J C; Kanatzidis, M G; Dravid, V P

    2011-06-15

    The Pb- and Sb- dual nanostructured PbTe system exhibits anomalous electronic transport behavior wherein the carrier mobility first increases and then decreases with increase in temperature. By combining in situ transmission electron microscopy observations and theoretical calculations based on energy filtering of charge carriers, we propose a plausible mechanism of charge transport based on interphase potential that is mediated by interdiffusion between coexisting Pb and Sb precipitates. These findings promise new strategies to enhance thermoelectric figure of merit via dual and multinanostructuring of miscible precipitates. PMID:21557606

  2. Fungal ABC transporters and microbial interactions in natural environments.

    PubMed

    Schoonbeek, Henk-jan; Raaijmakers, Jos M; De Waard, Maarten A

    2002-11-01

    In natural environments, microorganisms are exposed to a wide variety of antibiotic compounds produced by competing organisms. Target organisms have evolved various mechanisms of natural resistance to these metabolites. In this study, the role of ATP-binding cassette (ABC) transporters in interactions between the plant-pathogenic fungus Botrytis cinerea and antibiotic-producing Pseudomonas bacteria was investigated in detail. We discovered that 2,4-diacetylphloroglucinol, phenazine-1-carboxylic acid and phenazine-1-carboxamide (PCN), broad-spectrum antibiotics produced by Pseudomonas spp., induced expression of several ABC transporter genes in B. cinerea. Phenazines strongly induced expression of BcatrB, and deltaBcatrB mutants were significantly more sensitive to these antibiotics than their parental strain. Treatment of B. cinerea germlings with PCN strongly affected the accumulation of [14C]fludioxonil, a phenylpyrrole fungicide known to be transported by BcatrB, indicating that phenazines also are transported by BcatrB. Pseudomonas strains producing phenazines displayed a stronger antagonistic activity in vitro toward ABcatrB mutants than to the parental B. cinerea strain. On tomato leaves, phenazine-producing Pseudomonas strains were significantly more effective in reducing gray mold symptoms incited by a ABcatrB mutant than by the parental strain. We conclude that the ABC transporter BcatrB provides protection to B. cinerea in phenazine-mediated interactions with Pseudomonas spp. Collectively, these results indicate that fungal ABC transporters can play an important role in antibiotic-mediated interactions between bacteria and fungi in plant-associated environments. The implications of these findings for the implementation and sustainability of crop protection by antagonistic microorganisms are discussed. PMID:12423022

  3. Silicon Carbide Sensors and Electronics for Harsh Environment Applications

    NASA Technical Reports Server (NTRS)

    Evans, Laura J.

    2007-01-01

    Silicon carbide (SiC) semiconductor has been studied for electronic and sensing applications in extreme environment (high temperature, extreme vibration, harsh chemical media, and high radiation) that is beyond the capability of conventional semiconductors such as silicon. This is due to its near inert chemistry, superior thermomechanical and electronic properties that include high breakdown voltage and wide bandgap. An overview of SiC sensors and electronics work ongoing at NASA Glenn Research Center (NASA GRC) will be presented. The main focus will be two technologies currently being investigated: 1) harsh environment SiC pressure transducers and 2) high temperature SiC electronics. Work highlighted will include the design, fabrication, and application of SiC sensors and electronics, with recent advancements in state-of-the-art discussed as well. These combined technologies are studied for the goal of developing advanced capabilities for measurement and control of aeropropulsion systems, as well as enhancing tools for exploration systems.

  4. Contactless electronic transport in a bio-molecular junction

    SciTech Connect

    Hossain, Faruque M. Al-Dirini, Feras; Skafidas, Efstratios

    2014-07-28

    Molecular electronics hold promise for next generation ultra-low power, nano-scale integrated electronics. The main challenge in molecular electronics is to make a reliable interface between molecules and metal electrodes. Interfacing metals and molecules detrimentally affects the characteristics of nano-scale molecular electronic devices. It is therefore essential to investigate alternative arrangements such as contact-less tunneling gaps wherever such configurations are feasible. We conduct ab initio density functional theory and non-equilibrium Green's functions calculations to investigate the transport properties of a biocompatible glycine molecular junction. By analyzing the localized molecular orbital energy distributions and transmission probabilities in the transport-gap, we find a glycine molecule confined between two gold electrodes, without making a contact, is energetically stable and possesses high tunneling current resembling an excellent ohmic-like interface.

  5. Non equilibrium electronic transport in multilayered nanostructures

    NASA Astrophysics Data System (ADS)

    Cruz-Rojas, Jesus

    Recent advances in strongly correlated materials have produced systems with novel and interesting properties like high Tc superconductors, Mott insulators and others. These novel properties have sparked an interest in industry as well as in academia as new devices are being developed. One such kind of device that can be fabricated is a heterostructure, in which layers of different compounds are stacked in a single direction. Modern deposition techniques like electron beam epitaxy, in which atomic layers of different materials are deposited one at a time creating the device, are capable of fabricating heterostructures with atomic precision. We propose a technique to study heterostructures composed of strongly correlated materials out of equilibrium. By using the Keldysh Green's function formalism in the dynamical mean field theory (DMFT) framework the properties of a multilayered device are analyzed. The system is composed of infinite dimensional 2D lattices, stacked in the z direction. The first and last planes are then connected to a bulk reservoir, and several metallic planes are used to connect the bulk reservoir to the barrier region. The barrier region is the system of interest, also known as the device. The device is composed of a number of planes where the system correlations have been turned on. The correlations are then model by using the Falicov-Kimball Hamiltonian. The device is then connected to the bulk once again from the opposite side using metallic planes creating a symmetric system. In order to study the non equilibrium properties of the device a linear vector potential A(t) = A0 + tE is turned on a long time in the past for a unit of time and then turned off. This in turn will create a current in the bulk, in effect current biasing the device, as opposed to a voltage bias in which opposite sides of the device are held to a different potential. In this document we will explain the importance of the subject, we will derive and develop the algorithm

  6. Study of Electron Transport and Amplification in Diamond

    SciTech Connect

    Muller, Erik M.; Ben-Zvi, Ilan

    2013-03-31

    As a successful completion of this award, my group has demonstrated world-leading electron gain from diamond for use in a diamond-amplified photocathode. Also, using high-resolution photoemission measurements we were able to uncover exciting new physics of the electron emission mechanisms from hydrogen terminated diamond. Our work, through the continued support of HEP, has resulted in a greater understanding of the diamond material science, including current limits, charge transport modeling, and spatial uniformity.

  7. Origin of electronic transport of lithium phthalocyanine iodine crystal

    SciTech Connect

    Koike, Noritake; Oda, Masato; Shinozuka, Yuzo

    2013-12-04

    The electronic structures of Lithium Phthalocyanine Iodine are investigated using density functional theory. Comparing the band structures of several model crystals, the metallic conductivity of highly doped LiPcI{sub x} can be explained by the band of doped iodine. These results reveal that there is a new mechanism for electronic transport of doped organic semiconductors that the dopant band plays the main role.

  8. Two-stream approach to electron transport and thermalization

    SciTech Connect

    Stamnes, K.

    1981-04-01

    An explicit solution to the electron transport and energy degradation problem is presented in the two-stream approximation. The validity of this simple approach is discussed, and it is shown that it can be extended to high electron energies (appropriate for applications to auroras) provided the coupling between the two streams, described by the backscatter ratio, is correctly estimated. A simple formula for the backscatter ratio which can be used at all energies is derived.

  9. Simulation of electron transport during electron-beam-induced deposition of nanostructures

    PubMed Central

    Jeschke, Harald O; Valentí, Roser

    2013-01-01

    Summary We present a numerical investigation of energy and charge distributions during electron-beam-induced growth of tungsten nanostructures on SiO2 substrates by using a Monte Carlo simulation of the electron transport. This study gives a quantitative insight into the deposition of energy and charge in the substrate and in the already existing metallic nanostructures in the presence of the electron beam. We analyze electron trajectories, inelastic mean free paths, and the distribution of backscattered electrons in different compositions and at different depths of the deposit. We find that, while in the early stages of the nanostructure growth a significant fraction of electron trajectories still interacts with the substrate, when the nanostructure becomes thicker the transport takes place almost exclusively in the nanostructure. In particular, a larger deposit density leads to enhanced electron backscattering. This work shows how mesoscopic radiation-transport techniques can contribute to a model that addresses the multi-scale nature of the electron-beam-induced deposition (EBID) process. Furthermore, similar simulations can help to understand the role that is played by backscattered electrons and emitted secondary electrons in the change of structural properties of nanostructured materials during post-growth electron-beam treatments. PMID:24367747

  10. High Temperature Electronics for Intelligent Harsh Environment Sensors

    NASA Technical Reports Server (NTRS)

    Evans, Laura J.

    2008-01-01

    The development of intelligent instrumentation systems is of high interest in both public and private sectors. In order to obtain this ideal in extreme environments (i.e., high temperature, extreme vibration, harsh chemical media, and high radiation), both sensors and electronics must be developed concurrently in order that the entire system will survive for extended periods of time. The semiconductor silicon carbide (SiC) has been studied for electronic and sensing applications in extreme environment that is beyond the capability of conventional semiconductors such as silicon. The advantages of SiC over conventional materials include its near inert chemistry, superior thermomechanical properties in harsh environments, and electronic properties that include high breakdown voltage and wide bandgap. An overview of SiC sensors and electronics work ongoing at NASA Glenn Research Center (NASA GRC) will be presented. The main focus will be two technologies currently being investigated: 1) harsh environment SiC pressure transducers and 2) high temperature SiC electronics. Work highlighted will include the design, fabrication, and application of SiC sensors and electronics, with recent advancements in state-of-the-art discussed as well. These combined technologies are studied for the goal of developing advanced capabilities for measurement and control of aeropropulsion systems, as well as enhancing tools for exploration systems.

  11. Electron transport in magnetrons by a posteriori Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Costin, C.; Minea, T. M.; Popa, G.

    2014-02-01

    Electron transport across magnetic barriers is crucial in all magnetized plasmas. It governs not only the plasma parameters in the volume, but also the fluxes of charged particles towards the electrodes and walls. It is particularly important in high-power impulse magnetron sputtering (HiPIMS) reactors, influencing the quality of the deposited thin films, since this type of discharge is characterized by an increased ionization fraction of the sputtered material. Transport coefficients of electron clouds released both from the cathode and from several locations in the discharge volume are calculated for a HiPIMS discharge with pre-ionization operated in argon at 0.67 Pa and for very short pulses (few µs) using the a posteriori Monte Carlo simulation technique. For this type of discharge electron transport is characterized by strong temporal and spatial dependence. Both drift velocity and diffusion coefficient depend on the releasing position of the electron cloud. They exhibit minimum values at the centre of the race-track for the secondary electrons released from the cathode. The diffusion coefficient of the same electrons increases from 2 to 4 times when the cathode voltage is doubled, in the first 1.5 µs of the pulse. These parameters are discussed with respect to empirical Bohm diffusion.

  12. Transportation of a microwave environment over networks and the applications

    NASA Astrophysics Data System (ADS)

    Shoji, Yozo

    2012-01-01

    The concept of the transportation of a microwave environment over networks using a digitized Radio-on-Fibre (DRoF) technique as well as the concept of in-network microwave processing, which could make the concept of "wired and wireless network virtualization" into a reality, is discussed. The new applications to a radio-on-demand service (RoD), software-defined radio-aware network (SDRAN), and microwave environments cloud are introduced. 10-Gbps Ethernet based microwave-to-network interface converter (MiNIC) are developed and the transportation of multiple digital TV broadcasting signals is demonstrated. It is shown that the MiNIC should use more than 8-bits resolution in digitization of a microwave environment when 7 channels of TV signals are included in it. The concept of remote microwave environments observation over networks is demonstrated, where the frequency channel and received signal strength indication (RSSI) of the detected digital TV broadcasting signals are remotely monitored.

  13. Single-electron transport through a Mn12 (2-thiophenecarboxylate) single-molecule magnet

    NASA Astrophysics Data System (ADS)

    Ramsey, Christopher M.; Del Barco, Enrique; Mucciolo, Eduardo; Haque, Firoze; Khondaker, Saiful; Leuenberger, Michael; Mishra, Abhudaya; Christou, George

    2006-03-01

    We report single-electron transport measurements on Mn12 based single-molecule magnet, which has been functionalized with 2-thiophenecarboxylate ligands that bind to gold. The self-assembly of these molecules was confirmed by scanning probe microscopy and XPS measurements. Because it is well known that the molecule's environment within the crystal can have a profound influence on the quantum properties of the system, it is important to study the quantum spin dynamics in individual isolated molecules. Single electron transistor devices have been prepared for this purpose by electron beam lithography and electromigration. The transport properties of a single, isolated Mn12(2-thiophenecarboxylate) molecule were measured down to mK temperatures in a 3-D superconducting vector magnet with arbitrary field direction. The data are characteristic of a molecular single-electron transistor device where the SMM bridges the gap between two gold nanoelectrodes. Magnetic field and temperature dependence as well as theoretical aspects will be discussed.

  14. Physiology and biochemistry of reduction of azo compounds by Shewanella strains relevant to electron transport chain

    PubMed Central

    Gu, Ji-Dong

    2010-01-01

    Azo dyes are toxic, highly persistent, and ubiquitously distributed in the environments. The large-scale production and application of azo dyes result in serious environmental pollution of water and sediments. Bacterial azo reduction is an important process for removing this group of contaminants. Recent advances in this area of research reveal that azo reduction by Shewanella strains is coupled to the oxidation of electron donors and linked to the electron transport and energy conservation in the cell membrane. Up to date, several key molecular components involved in this reaction have been identified and the primary electron transportation system has been proposed. These new discoveries on the respiration pathways and electron transfer for bacterial azo reduction has potential biotechnological implications in cleaning up contaminated sites. PMID:20706834

  15. Physiology and biochemistry of reduction of azo compounds by Shewanella strains relevant to electron transport chain.

    PubMed

    Hong, Yi-Guo; Gu, Ji-Dong

    2010-10-01

    Azo dyes are toxic, highly persistent, and ubiquitously distributed in the environments. The large-scale production and application of azo dyes result in serious environmental pollution of water and sediments. Bacterial azo reduction is an important process for removing this group of contaminants. Recent advances in this area of research reveal that azo reduction by Shewanella strains is coupled to the oxidation of electron donors and linked to the electron transport and energy conservation in the cell membrane. Up to date, several key molecular components involved in this reaction have been identified and the primary electron transportation system has been proposed. These new discoveries on the respiration pathways and electron transfer for bacterial azo reduction has potential biotechnological implications in cleaning up contaminated sites.

  16. Photosynthetic electron transport system promotes synthesis of Au-nanoparticles.

    PubMed

    Shabnam, Nisha; Pardha-Saradhi, P

    2013-01-01

    In this communication, a novel, green, efficient and economically viable light mediated protocol for generation of Au-nanoparticles using most vital organelle, chloroplasts, of the plant system is portrayed. Thylakoids/chloroplasts isolated from Potamogeton nodosus (an aquatic plant) and Spinacia oleracea (a terrestrial plant) turned Au³⁺ solutions purple in presence of light of 600 µmol m⁻² s⁻¹ photon flux density (PFD) and the purple coloration intensified with time. UV-Vis spectra of these purple colored solutions showed absorption peak at ∼545 nm which is known to arise due to surface plasmon oscillations specific to Au-nanoparticles. However, thylakoids/chloroplasts did not alter color of Au³⁺ solutions in dark. These results clearly demonstrated that photosynthetic electron transport can reduce Au³⁺ to Au⁰ which nucleate to form Au-nanoparticles in presence of light. Transmission electron microscopic studies revealed that Au-nanoparticles generated by light driven photosynthetic electron transport system of thylakoids/chloroplasts were in range of 5-20 nm. Selected area electron diffraction and powder X-ray diffraction indicated crystalline nature of these nanoparticles. Energy dispersive X-ray confirmed that these nanoparticles were composed of Au. To confirm the potential of light driven photosynthetic electron transport in generation of Au-nanoparticles, thylakoids/chloroplasts were tested for their efficacy to generate Au-nanoparticles in presence of light of PFD ranging from 60 to 600 µmol m⁻² s⁻¹. The capacity of thylakoids/chloroplasts to generate Au-nanoparticles increased remarkably with increase in PFD, which further clearly demonstrated potential of light driven photosynthetic electron transport in reduction of Au³⁺ to Au⁰ to form nanoparticles. The light driven donation of electrons to metal ions by thylakoids/chloroplasts can be exploited for large scale production of nanoparticles. PMID:23976990

  17. Photosynthetic electron transport system promotes synthesis of Au-nanoparticles.

    PubMed

    Shabnam, Nisha; Pardha-Saradhi, P

    2013-01-01

    In this communication, a novel, green, efficient and economically viable light mediated protocol for generation of Au-nanoparticles using most vital organelle, chloroplasts, of the plant system is portrayed. Thylakoids/chloroplasts isolated from Potamogeton nodosus (an aquatic plant) and Spinacia oleracea (a terrestrial plant) turned Au³⁺ solutions purple in presence of light of 600 µmol m⁻² s⁻¹ photon flux density (PFD) and the purple coloration intensified with time. UV-Vis spectra of these purple colored solutions showed absorption peak at ∼545 nm which is known to arise due to surface plasmon oscillations specific to Au-nanoparticles. However, thylakoids/chloroplasts did not alter color of Au³⁺ solutions in dark. These results clearly demonstrated that photosynthetic electron transport can reduce Au³⁺ to Au⁰ which nucleate to form Au-nanoparticles in presence of light. Transmission electron microscopic studies revealed that Au-nanoparticles generated by light driven photosynthetic electron transport system of thylakoids/chloroplasts were in range of 5-20 nm. Selected area electron diffraction and powder X-ray diffraction indicated crystalline nature of these nanoparticles. Energy dispersive X-ray confirmed that these nanoparticles were composed of Au. To confirm the potential of light driven photosynthetic electron transport in generation of Au-nanoparticles, thylakoids/chloroplasts were tested for their efficacy to generate Au-nanoparticles in presence of light of PFD ranging from 60 to 600 µmol m⁻² s⁻¹. The capacity of thylakoids/chloroplasts to generate Au-nanoparticles increased remarkably with increase in PFD, which further clearly demonstrated potential of light driven photosynthetic electron transport in reduction of Au³⁺ to Au⁰ to form nanoparticles. The light driven donation of electrons to metal ions by thylakoids/chloroplasts can be exploited for large scale production of nanoparticles.

  18. Transport Experiments on 2D Correlated Electron Physics in Semiconductors

    SciTech Connect

    Tsui, Daniel

    2014-03-24

    This research project was designed to investigate experimentally the transport properties of the 2D electrons in Si and GaAs, two prototype semiconductors, in several new physical regimes that were previously inaccessible to experiments. The research focused on the strongly correlated electron physics in the dilute density limit, where the electron potential energy to kinetic energy ratio rs>>1, and on the fractional quantum Hall effect related physics in nuclear demagnetization refrigerator temperature range on samples with new levels of purity and controlled random disorder.

  19. Electron energy transport and magnetic curvature driven modes

    SciTech Connect

    Coppi, B.; Tang, W.M.

    1984-10-01

    A transport coefficient for anomalous electron thermal conduction is constructed on the basis of the so-called Principle of Profile Consistency. It is assumed that the relevant modes in plasma where a substantial fraction of the electron population is magnetically trapped produce magnetic reconnection at a microscopic level and are driven by the combined effects of the plasma pressure gradient and the magnetic field curvature. Consequently, the scaling for the electron energy confinement time exhibits a strongly favorable dependence on the radius of magnetic curvature.

  20. Investigation of electron beam transport in a helical undulator

    SciTech Connect

    Jeong, Y.U.; Lee, B.C.; Kim, S.K.

    1995-12-31

    Lossless transport of electrons through the undulator is essential for CW operation of the FELs driven by recirculating electrostatic accelerators. We calculate the transport ratio of an electron beam in a helical undulator by using a 3-D simulation code and compare the results with the experimental results. The energy and the current of the electron beam are 400 keV and 2 A, respectively. The 3-D distribution of the magnetic field of a practical permanent-magnet helical undulator is measured and is used in the calculations. The major parameters of the undutlator are : period = 32 mm, number of periods = 20, number of periods in adiabatic region = 3.5, magnetic field strength = 1.3 kG. The transport ratio is very sensitive to the injection condition of the electron beam such as the emittance, the diameter, the divergence, etc.. The injection motion is varied in the experiments by changing the e-gun voltage or the field strength of the focusing magnet located at the entrance of the undulator. It is confirmed experimentally and with simulations that most of the beam loss occurs at the adiabatic region of the undulator regardless of the length of the adiabatic region The effect of axial guiding magnetic field on the beam finish is investigated. According to the simulations, the increase of the strength of axial magnetic field from 0 to 1 kG results in the increase of the transport ratio from 15 % to 95%.

  1. ELECTRONIC AND TRANSPORT PROPERTIES OF THERMOELECTRIC Ru2Si3

    NASA Astrophysics Data System (ADS)

    Singh, David J.; Parker, David

    2013-10-01

    We report calculations of the doping and temperature dependent thermopower of Ru2Si3 based on Boltzmann transport theory and the first principles electronic structure. We find that the performance reported to date can be significantly improved by optimization of the doping level and that ultimately n-type should have higher ZT than p-type.

  2. Requirement for Coenzyme Q in Plasma Membrane Electron Transport

    NASA Astrophysics Data System (ADS)

    Sun, I. L.; Sun, E. E.; Crane, F. L.; Morre, D. J.; Lindgren, A.; Low, H.

    1992-12-01

    Coenzyme Q is required in the electron transport system of rat hepatocyte and human erythrocyte plasma membranes. Extraction of coenzyme Q from the membrane decreases NADH dehydrogenase and NADH:oxygen oxidoreductase activity. Addition of coenzyme Q to the extracted membrane restores the activity. Partial restoration of activity is also found with α-tocopherylquinone, but not with vitamin K_1. Analogs of coenzyme Q inhibit NADH dehydrogenase and oxidase activity and the inhibition is reversed by added coenzyme Q. Ferricyanide reduction by transmembrane electron transport from HeLa cells is inhibited by coenzyme Q analogs and restored with added coenzyme Q10. Reduction of external ferricyanide and diferric transferrin by HeLa cells is accompanied by proton release from the cells. Inhibition of the reduction by coenzyme Q analogs also inhibits the proton release, and coenzyme Q10 restores the proton release activity. Trans-plasma membrane electron transport stimulates growth of serum-deficient cells, and added coenzyme Q10 increases growth of HeLa (human adenocarcinoma) and BALB/3T3 (mouse fibroblast) cells. The evidence is consistent with a function for coenzyme Q in a trans-plasma membrane electron transport system which influences cell growth.

  3. Neoclassical electron and ion transport in toroidally rotating plasmas

    SciTech Connect

    Sugama, H.; Horton, W.

    1997-06-01

    Neoclassical transport processes of electrons and ions are investigated in detail for toroidally rotating axisymmetric plasmas with large flow velocities on the order of the ion thermal speed. The Onsager relations for the flow-dependent neoclassical transport coefficients are derived from the symmetry properties of the drift kinetic equation with the self-adjoint collision operator. The complete neoclassical transport matrix with the Onsager symmetry is obtained for the rotating plasma consisting of electrons and single-species ions in the Pfirsch{endash}Schl{umlt u}ter and banana regimes. It is found that the inward banana fluxes of particles and toroidal momentum are driven by the parallel electric field, which are phenomena coupled through the Onsager symmetric off-diagonal coefficients to the parallel currents caused by the radial thermodynamic forces conjugate to the inward fluxes, respectively. {copyright} {ital 1997 American Institute of Physics.}

  4. Relativistic electron transport and bremsstrahlung production in solar flares

    NASA Astrophysics Data System (ADS)

    Miller, James A.; Ramaty, Reuven

    1989-09-01

    A Monte Carlo simulation of ultrarelativistic electron transport in solar flare magnetic loops has been developed. It includes Coulomb, synchrotron, and bremsstrahlung energy losses; pitch-angle scattering by Alfven and whistler turbulence in the coronal region of the loop; and magnetic mirroring in the converging magnetic flux tubes beneath the transition region. Depth distributions, time profiles, energy spectra, and angular distributions of the resulting bremsstrahlung emission are calculated. It is found that both the preferential detection of solar flares with greater than 10 MeV emission near the limb of the sun and the observation of ultrarelativistic electron bremsstrahlung from flares on the disk are consequences of the loop transport model. The declining portions of the observed time profiles of greater than 10 MeV emission from solar flares can also be accounted for, and it is proposed that these portions are determined by transport and not acceleration.

  5. Energy-filtered Electron Transport Structures for Low-power Low-noise 2-D Electronics

    PubMed Central

    Pan, Xuan; Qiu, Wanzhi; Skafidas, Efstratios

    2016-01-01

    In addition to cryogenic techniques, energy filtering has the potential to achieve high-performance low-noise 2-D electronic systems. Assemblies based on graphene quantum dots (GQDs) have been demonstrated to exhibit interesting transport properties, including resonant tunnelling. In this paper, we investigate GQDs based structures with the goal of producing energy filters for next generation lower-power lower-noise 2-D electronic systems. We evaluate the electron transport properties of the proposed GQD device structures to demonstrate electron energy filtering and the ability to control the position and magnitude of the energy passband by appropriate device dimensioning. We also show that the signal-to-thermal noise ratio performance of the proposed nanoscale device can be modified according to device geometry. The tunability of two-dimensional GQD structures indicates a promising route for the design of electron energy filters to produce low-power and low-noise electronics. PMID:27796343

  6. Applications and fabrication of flasks for hostile environment electronics

    SciTech Connect

    Randall, R.R.; Craik, G.C.

    1988-02-01

    The use of electronic instrumentation in a high temperature environment such as a wellbore requires a choice between two design techniques. The preferred technique is to design a system with high temperature electronics. When there are obstacles to such a design, a workable second choice is to use a Dewar flask to provide a protected environment. Design options for building a flask and engineering information on how to use flasks is provided. Selected well logging services are made possible by using Dewar flask technology.

  7. Electron transport mechanisms in polymer-carbon sphere composites

    NASA Astrophysics Data System (ADS)

    Nieves, Cesar A.; Ramos, Idalia; Pinto, Nicholas J.; Zimbovskaya, Natalya A.

    2016-07-01

    A set of uniform carbon microspheres (CSs) whose diameters have the order of 0.125 μm to 10 μm was prepared from aqueous sucrose solution by means of hydrothermal carbonization of sugar molecules. A pressed pellet was composed by mixing CSs with polyethylene oxide (PEO). Electrical characterization of the pellet was carried out showing Ohmic current-voltage characteristics and temperature-dependent conductivity in the range of 80 K electron transport. It was shown that thermally induced electron tunneling between adjacent spheres may take on an important part in the electron transport through the CS/PEO composites.

  8. Electron transport in naphthylamine-based organic compounds

    NASA Astrophysics Data System (ADS)

    Tse, S. C.; Kwok, K. C.; So, S. K.

    2006-12-01

    Two naphthylamine-based hole transporters, namely, N ,N'-diphenyl-N ,N'-bis(1-naphthyl)(1,1'-biphenyl)-4,4'diamine (NPB) and 4,4',4″-tris(n-(2-naphthyl)-n-phenyl-amino)-triphenylamine (2TNATA), were found to possess electron transporting (ET) abilities. From time-of-flight measurements, values of electron mobilities for NPB and 2TNATA are (6-9)×10-4 and (1-3)×10-4cm2/Vs, respectively, under an applied electric field range of 0.04-0.8MV/cm at 290K. An organic light-emitting diode that employed NPB as the ET material was demonstrated. The electron conducting mechanism of NPB and 2TNATA in relation to the Marcus theory [Rev. Mod. Phys. 65, 599 (1993)] from quantum chemistry will be discussed.

  9. Electronic transport experiments on osmium-adatom-decorated graphene

    NASA Astrophysics Data System (ADS)

    Elias, Jamie; Henriksen, Erik

    Monolayer graphene is theoretically predicted to inherit a spin-orbit coupling from a dilute coating of certain transition metal adatoms. To explore these predictions we have constructed a cryogenic probe capable of in situ thermal annealing of graphene followed immediately by electronic transport measurements and controlled deposition of sub-monolayer coatings of most any metal. Previously a light coating of indium on graphene was investigated, and found to transfer electrons to graphene and reduce the mobility although no evidence of an induced spin-orbit coupling was seen. We are now depositing osmium and tungsten on graphene devices. Our initial results show an unexpected hole-doping and a sizable increase in resistance of the sample. We will report our progress on characterizing these samples by electronic transport measurements.

  10. Built environment influences on healthy transportation choices: bicycling versus driving.

    PubMed

    Winters, Meghan; Brauer, Michael; Setton, Eleanor M; Teschke, Kay

    2010-12-01

    A growing body of evidence links the built environment to physical activity levels, health outcomes, and transportation behaviors. However, little of this research has focused on cycling, a sustainable transportation option with great potential for growth in North America. This study examines associations between decisions to bicycle (versus drive) and the built environment, with explicit consideration of three different spatial zones that may be relevant in travel behavior: trip origins, trip destinations, and along the route between. We analyzed 3,280 utilitarian bicycle and car trips in Metro Vancouver, Canada made by 1,902 adults, including both current and potential cyclists. Objective measures were developed for built environment characteristics related to the physical environment, land use patterns, the road network, and bicycle-specific facilities. Multilevel logistic regression was used to model the likelihood that a trip was made by bicycle, adjusting for trip distance and personal demographics. Separate models were constructed for each spatial zone, and a global model examined the relative influence of the three zones. In total, 31% (1,023 out of 3,280) of trips were made by bicycle. Increased odds of bicycling were associated with less hilliness; higher intersection density; less highways and arterials; presence of bicycle signage, traffic calming, and cyclist-activated traffic lights; more neighborhood commercial, educational, and industrial land uses; greater land use mix; and higher population density. Different factors were important within each spatial zone. Overall, the characteristics of routes were more influential than origin or destination characteristics. These findings indicate that the built environment has a significant influence on healthy travel decisions, and spatial context is important. Future research should explicitly consider relevant spatial zones when investigating the relationship between physical activity and urban form.

  11. Transport in nanoscale systems: hydrodynamics, turbulence, and local electron heating

    NASA Astrophysics Data System (ADS)

    di Ventra, Massimiliano

    2007-03-01

    Transport in nanoscale systems is usually described as an open-boundary scattering problem. This picture, however, says nothing about the dynamical onset of steady states, their microscopic nature, or their dependence on initial conditions [1]. In order to address these issues, I will first describe the dynamical many-particle state via an effective quantum hydrodynamic theory [2]. This approach allows us to predict a series of novel phenomena like turbulence of the electron liquid [2], local electron heating in nanostructures [3], and the effect of electron viscosity on resistance [4]. I will provide both analytical results and numerical examples of first-principles electron dynamics in nanostructures using the above approach. I will also discuss possible experimental tests of our predictions. Work supported in part by NSF and DOE. [1] N. Bushong, N. Sai and M. Di Ventra, ``Approach to steady-state transport in nanoscale systems'' Nano Letters, 5 2569 (2005); M. Di Ventra and T.N. Todorov, ``Transport in nanoscale systems: the microcanonical versus grand-canonical picture,'' J. Phys. Cond. Matt. 16, 8025 (2004). [2] R. D'Agosta and M. Di Ventra, ``Hydrodynamic approach to transport and turbulence in nanoscale conductors,'' cond-mat/05123326; J. Phys. Cond. Matt., in press. [3] R. D'Agosta, N. Sai and M. Di Ventra, ``Local electron heating in nanoscale conductors,'' cond-mat/0605312; Nano Letters, in press. [4] N. Sai, M. Zwolak, G. Vignale and M. Di Ventra, ``Dynamical corrections to the DFT-LDA electron conductance in nanoscale systems,'' Phys. Rev. Lett. 94, 186810 (2005).

  12. Ultrafast electron transport in graphene and magnetic nanostructures

    NASA Astrophysics Data System (ADS)

    Turchinovich, Dmitry

    2016-03-01

    Ultrafast terahertz spectroscopy is an ideal tool for observation of dynamics of charge, lattice and spin in solids on the most elementary timescale: in the regime ωτ ~ 1, where ω is the electromagnetic wave oscillation frequency, and τ is the characteristic timescale at which the fundamental phenomena in the three subsystems comprising the solid occur. In this paper two case studies will be discussed. (i) Ultrafast electron transport in graphene. We will show, that the free-carrier conductivity of graphene in arbitrary ultrafast, (sub-)picosecond electric fields is defined by the thermodynamic balance maintained within the electronic structure of graphene acting as thermalized electron gas. Within this simple thermodynamic picture, the electron gas quasi-instantaneously increases its temperature by absorbing the energy of driving ultrafast electric field, and at the same time cools down via a time-retarded, few picosecond-long process of phonon emission. The asymmetry in electron heating and cooling dynamics leads to heat accumulation in the electron population of graphene, concomitantly lowering the chemical potential for hotter electrons, and thereby reducing the intraband conductivity of graphene - an effect crucially important for understanding of ultrafast graphene transistors and photodetectors. (ii) We will also discuss the fundamental observation of spin-controlled electron conduction of Fermilevel electrons in ferromagnetic metals, and will directly quantify the Mott picture of conduction in ferromagnets - the effect directly employed in modern magnetic sensor technologies such as giant magnetoresistance.

  13. General theory of electronic transport in molecular crystals. I. Local linear electron-phonon coupling

    NASA Astrophysics Data System (ADS)

    Silbey, R.; Munn, R. W.

    1980-02-01

    An improved general theory of electronic transport in molecular crystals with local linear electron-phonon coupling is presented. It is valid for arbitrary electronic and phonon bandwidths and for arbitrary electron-phonon coupling strength, yielding small-polaron theory for narrow electronic bands and strong coupling, and semiconductor theory for wide electronic bands and weak coupling. Detailed results are derived for electronic excitations fully clothed with phonons and having a bandwidth no larger than the phonon frequency; the electronic and phonon densities of states are taken as Gaussian for simplicity. The dependence of the diffusion coefficient on temperature and on the other parameters is analyzed thoroughly. The calculated behavior provides a rational interpretation of observed trends in the magnitude and temperature dependence of charge-carrier drift mobilities in molecular crystals.

  14. Transportable Applications Environment Plus, Version 5.1

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Transportable Applications Environment Plus (TAE+) computer program providing integrated, portable programming environment for developing and running application programs based on interactive windows, text, and graphical objects. Enables both programmers and nonprogrammers to construct own custom application interfaces easily and to move interfaces and application programs to different computers. Used to define corporate user interface, with noticeable improvements in application developer's and end user's learning curves. Main components are; WorkBench, What You See Is What You Get (WYSIWYG) software tool for design and layout of user interface; and WPT (Window Programming Tools) Package, set of callable subroutines controlling user interface of application program. WorkBench and WPT's written in C++, and remaining code written in C.

  15. Sherlock: A Coached Practice Environment for an Electronics Troubleshooting Job.

    ERIC Educational Resources Information Center

    Lesgold, Alan; And Others

    "Sherlock" is a computer-based, supported practice environment for a complex troubleshooting job in Air Force electronics. The program was developed to raise the level of troubleshooting knowledge of avionics technicians. This describes the training problem for which Sherlock was developed, the principles behind its development, and its…

  16. Expression and Association Rights of School Employees in Electronic Environments

    ERIC Educational Resources Information Center

    Bathon, Justin M.

    2012-01-01

    Many of the recent legal decisions regarding public employee expression, particularly in electronic environments, run counter to the culture being facilitated by the Internet. This article uses a legal analysis to examine recent decisions and then considers those legal positions within the context of digital expression. (Contains 2 notes.)

  17. Electronic transport in benzodifuran single-molecule transistors

    NASA Astrophysics Data System (ADS)

    Xiang, An; Li, Hui; Chen, Songjie; Liu, Shi-Xia; Decurtins, Silvio; Bai, Meilin; Hou, Shimin; Liao, Jianhui

    2015-04-01

    Benzodifuran (BDF) single-molecule transistors have been fabricated in electromigration break junctions for electronic measurements. The inelastic electron tunneling spectrum validates that the BDF molecule is the pathway of charge transport. The gating effect is analyzed in the framework of a single-level tunneling model combined with transition voltage spectroscopy (TVS). The analysis reveals that the highest occupied molecular orbital (HOMO) of the thiol-terminated BDF molecule dominates the charge transport through Au-BDF-Au junctions. Moreover, the energy shift of the HOMO caused by the gate voltage is the main reason for conductance modulation. In contrast, the electronic coupling between the BDF molecule and the gold electrodes, which significantly affects the low-bias junction conductance, is only influenced slightly by the applied gate voltage. These findings will help in the design of future molecular electronic devices.Benzodifuran (BDF) single-molecule transistors have been fabricated in electromigration break junctions for electronic measurements. The inelastic electron tunneling spectrum validates that the BDF molecule is the pathway of charge transport. The gating effect is analyzed in the framework of a single-level tunneling model combined with transition voltage spectroscopy (TVS). The analysis reveals that the highest occupied molecular orbital (HOMO) of the thiol-terminated BDF molecule dominates the charge transport through Au-BDF-Au junctions. Moreover, the energy shift of the HOMO caused by the gate voltage is the main reason for conductance modulation. In contrast, the electronic coupling between the BDF molecule and the gold electrodes, which significantly affects the low-bias junction conductance, is only influenced slightly by the applied gate voltage. These findings will help in the design of future molecular electronic devices. Electronic supplementary information (ESI) available: The fabrication procedure for BDF single

  18. Transport of the plasma sheet electrons to the geostationary distances

    NASA Astrophysics Data System (ADS)

    Ganushkina, N. Y.; Amariutei, O. A.; Shprits, Y. Y.; Liemohn, M. W.

    2013-01-01

    Abstract<p label="1">The <span class="hlt">transport</span> and acceleration of low-energy <span class="hlt">electrons</span> (50-250 keV) from the plasma sheet to the geostationary orbit were investigated. Two moderate storm events, which occurred on 6-7 November 1997 and 12-14 June 2005, were modeled using the Inner Magnetosphere Particle <span class="hlt">Transport</span> and Acceleration model (IMPTAM) with the boundary set at 10 RE in the plasma sheet. The output of the IMPTAM was compared to the observed <span class="hlt">electron</span> fluxes in four energy ranges (50-225 keV) measured by the Synchronous Orbit Particle Analyzer instrument onboard the Los Alamos National Laboratory spacecraft. It was found that the large-scale convection in combination with substorm-associated impulsive fields is the drivers of the <span class="hlt">transport</span> of plasma sheet <span class="hlt">electrons</span> from 10 RE to geostationary orbit at 6.6 RE during storm times. The addition of radial diffusion had no significant influence on the modeled <span class="hlt">electron</span> fluxes. At the same time, the modeled <span class="hlt">electron</span> fluxes are one (two) order(s) smaller than the observed ones for 50-150 keV (150-225 keV) <span class="hlt">electrons</span>, respectively, most likely due to inaccuracy of <span class="hlt">electron</span> boundary conditions. The loss processes due to wave-particle interactions were not considered. The choice of the large-scale convection electric field model used in simulations did not have a significant influence on the modeled <span class="hlt">electron</span> fluxes, since there is not much difference between the equipotential contours given by the Volland-Stern and the Boyle et al. (1997) models at distances from 10 to 6.6 RE in the plasma sheet. Using the TS05 model for the background magnetic field instead of the T96 model resulted in larger deviations of the modeled <span class="hlt">electron</span> fluxes from the observed ones due to specific features of the TS05 model. The increase in the modeled <span class="hlt">electron</span> fluxes can be as large as two orders of magnitude when substorm-associated electromagnetic fields were taken into account. The obtained model distribution of low-energy <span class="hlt">electron</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSM44A..08G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSM44A..08G"><span id="translatedtitle"><span class="hlt">Transport</span> of the plasma sheet <span class="hlt">electrons</span> to the geostationary distances</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ganushkina, N. Y.; Amariutei, O. A.; Shprits, Y.; Liemohn, M. W.</p> <p>2012-12-01</p> <p>The <span class="hlt">transport</span> and acceleration of low energy <span class="hlt">electrons</span> (10-250 keV) from the plasma sheet to the geostationary orbit were investigated. Two moderate storm events, which occurred on November 6-7, 1997 and June 12-14, 2005, were modeled using the Inner Magnetosphere Particle <span class="hlt">Transport</span> and Acceleration model (IMPTAM) with the boundary set at 10 RE in the plasma sheet. The output of the IMPTAM model was compared to the observed <span class="hlt">electron</span> fluxes in four energy ranges measured onboard the LANL spacecraft by the SOPA instrument. It was found that the large-scale convection in combination with substorm-associated impulsive fields are the drivers of the <span class="hlt">transport</span> of plasma sheet <span class="hlt">electrons</span> from 10 RE to geostationary orbit at 6.6 RE during storm times. The addition of radial diffusion had no significant influence on the modeled <span class="hlt">electron</span> fluxes. At the same time, comparison between the modeled <span class="hlt">electron</span> fluxes and observed ones showed two orders of difference most likely due to inaccuracy of <span class="hlt">electron</span> boundary conditions and omission of the important loss processes due to wave-particle interactions. This did not allow us to accuractly reproduce the dynamics of 150-225 keV <span class="hlt">electron</span> fluxes. The choice of the large-scale convection electric field model used in simulations did not significantly influence on the modeled <span class="hlt">electron</span> fluxes, since there is not much difference between the equipotential contours given by the Volland-Stern and Boyle et al. [1997] models at the distances from 10 to 6.6 RE in the plasma sheet. Using the TS05 model for the background magnetic field instead of the T96 model resulted in larger deviations of the modeled <span class="hlt">electron</span> fluxes from the observed ones due to specific features of the TS05 model. The increase in the modeled <span class="hlt">electron</span> fluxes can be as large as three orders of magnitude when substorm-associated electromagnetic fields were taken into account. The obtained model distribution of low energy <span class="hlt">electron</span> fluxes can be used as an input to the radiation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1096488','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1096488"><span id="translatedtitle">LDRD project 151362 : low energy <span class="hlt">electron</span>-photon <span class="hlt">transport</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kensek, Ronald Patrick; Hjalmarson, Harold Paul; Magyar, Rudolph J.; Bondi, Robert James; Crawford, Martin James</p> <p>2013-09-01</p> <p>At sufficiently high energies, the wavelengths of <span class="hlt">electrons</span> and photons are short enough to only interact with one atom at time, leading to the popular %E2%80%9Cindependent-atom approximation%E2%80%9D. We attempted to incorporate atomic structure in the generation of cross sections (which embody the modeled physics) to improve <span class="hlt">transport</span> at lower energies. We document our successes and failures. This was a three-year LDRD project. The core team consisted of a radiation-<span class="hlt">transport</span> expert, a solid-state physicist, and two DFT experts.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Nanot..27m5302S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nanot..27m5302S"><span id="translatedtitle">Geometric effects in the <span class="hlt">electronic</span> <span class="hlt">transport</span> of deformed nanotubes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santos, Fernando; Fumeron, Sébastien; Berche, Bertrand; Moraes, Fernando</p> <p>2016-04-01</p> <p>Quasi-two-dimensional systems may exibit curvature, which adds three-dimensional influence to their internal properties. As shown by da Costa (1981 Phys. Rev. A 23 1982-7), charged particles moving on a curved surface experience a curvature-dependent potential which greatly influence their dynamics. In this paper, we study the <span class="hlt">electronic</span> ballistic <span class="hlt">transport</span> in deformed nanotubes. The one-<span class="hlt">electron</span> Schrödinger equation with open boundary conditions is solved numerically with a flexible MAPLE code made available as supplementary data. We find that the curvature of the deformations indeed has strong effects on the <span class="hlt">electron</span> dynamics, suggesting its use in the design of nanotube-based <span class="hlt">electronic</span> devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22051363','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22051363"><span id="translatedtitle">Spatially resolved study of primary <span class="hlt">electron</span> <span class="hlt">transport</span> in magnetic cusps</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hubble, Aimee A.; Foster, John E.</p> <p>2012-01-15</p> <p>Spatially resolved primary <span class="hlt">electron</span> current density profiles were measured using a planar Langmuir probe in the region above a magnetic cusp in a small ion thruster discharge chamber. The probe current maps obtained were used to study the <span class="hlt">electron</span> collection mechanics in the cusp region in the limit of zero gas flow and no plasma production, and they allowed for the visualization of primary <span class="hlt">electron</span> <span class="hlt">transport</span> through the cusp. Attenuation coefficients and loss widths were calculated as a function of probe distance above the anode at various operating conditions. Finally, the collection mechanics between two magnetic cusps were studied and compared. It was found that primary <span class="hlt">electron</span> collection was dominated by the upstream magnet ring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/3847','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/3847"><span id="translatedtitle">The macro response Monte Carlo method for <span class="hlt">electron</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Svatos, M M</p> <p>1998-09-01</p> <p>The main goal of this thesis was to prove the feasibility of basing <span class="hlt">electron</span> depth dose calculations in a phantom on first-principles single scatter physics, in an amount of time that is equal to or better than current <span class="hlt">electron</span> Monte Carlo methods. The Macro Response Monte Carlo (MRMC) method achieves run times that are on the order of conventional <span class="hlt">electron</span> <span class="hlt">transport</span> methods such as condensed history, with the potential to be much faster. This is possible because MRMC is a Local-to-Global method, meaning the problem is broken down into two separate <span class="hlt">transport</span> calculations. The first stage is a local, in this case, single scatter calculation, which generates probability distribution functions (PDFs) to describe the <span class="hlt">electron</span>'s energy, position and trajectory after leaving the local geometry, a small sphere or "kugel" A number of local kugel calculations were run for calcium and carbon, creating a library of kugel data sets over a range of incident energies (0.25 MeV - 8 MeV) and sizes (0.025 cm to 0.1 cm in radius). The second <span class="hlt">transport</span> stage is a global calculation, where steps that conform to the size of the kugels in the library are taken through the global geometry. For each step, the appropriate PDFs from the MRMC library are sampled to determine the <span class="hlt">electron</span>'s new energy, position and trajectory. The <span class="hlt">electron</span> is immediately advanced to the end of the step and then chooses another kugel to sample, which continues until <span class="hlt">transport</span> is completed. The MRMC global stepping code was benchmarked as a series of subroutines inside of the Peregrine Monte Carlo code. It was compared to Peregrine's class II condensed history <span class="hlt">electron</span> <span class="hlt">transport</span> package, EGS4, and MCNP for depth dose in simple phantoms having density inhomogeneities. Since the kugels completed in the library were of relatively small size, the zoning of the phantoms was scaled down from a clinical size, so that the energy deposition algorithms for spreading dose across 5-10 zones per kugel could be tested. Most</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010055260','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010055260"><span id="translatedtitle">Low Energy <span class="hlt">Electrons</span> in the Mars Plasma <span class="hlt">Environment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Link, Richard</p> <p>2001-01-01</p> <p>The ionosphere of Mars is rather poorly understood. The only direct measurements were performed by the Viking 1 and 2 landers in 1976, both of which carried a Retarding Potential Analyzer. The RPA was designed to measure ion properties during the descent, although <span class="hlt">electron</span> fluxes were estimated from changes in the ion currents. Using these derived low-energy <span class="hlt">electron</span> fluxes, Mantas and Hanson studied the photoelectron and the solar wind <span class="hlt">electron</span> interactions with the atmosphere and ionosphere of Mars. Unanswered questions remain regarding the origin of the low-energy <span class="hlt">electron</span> fluxes in the vicinity of the Mars plasma boundary. Crider, in an analysis of Mars Global Surveyor Magnetometer/<span class="hlt">Electron</span> Reflectometer measurements, has attributed the formation of the magnetic pile-up boundary to <span class="hlt">electron</span> impact ionization of exospheric neutral species by solar wind <span class="hlt">electrons</span>. However, the role of photoelectrons escaping from the lower ionosphere was not determined. In the proposed work, we will examine the role of solar wind and ionospheric photoelectrons in producing ionization in the upper ionosphere of Mars. Low-energy (< 4 keV) <span class="hlt">electrons</span> will be modeled using the two-stream <span class="hlt">electron</span> <span class="hlt">transport</span> code of Link. The code models both external (solar wind) and internal (photoelectron) sources of ionization, and accounts for Auger <span class="hlt">electron</span> production. The code will be used to analyze Mars Global Surveyor measurements of solar wind and photoelectrons down to altitudes below 200 km in the Mars ionosphere, in order to determine the relative roles of solar wind and escaping photoelectrons in maintaining plasma densities in the region of the Mars plasma boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/503467','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/503467"><span id="translatedtitle">Fabrication and <span class="hlt">electronic</span> <span class="hlt">transport</span> studies of single nanocrystal systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Klein, D L</p> <p>1997-05-01</p> <p>Semiconductor and metallic nanocrystals exhibit interesting <span class="hlt">electronic</span> <span class="hlt">transport</span> behavior as a result of electrostatic and quantum mechanical confinement effects. These effects can be studied to learn about the nature of <span class="hlt">electronic</span> states in these systems. This thesis describes several techniques for the <span class="hlt">electronic</span> study of nanocrystals. The primary focus is the development of novel methods to attach leads to prefabricated nanocrystals. This is because, while nanocrystals can be readily synthesized from a variety of materials with excellent size control, means to make electrical contact to these nanocrystals are limited. The first approach that will be described uses scanning probe microscopy to first image and then electrically probe surfaces. It is found that <span class="hlt">electronic</span> investigations of nanocrystals by this technique are complicated by tip-sample interactions and environmental factors such as salvation and capillary forces. Next, an atomic force microscope technique for the catalytic patterning of the surface of a self assembled monolayer is described. In principle, this nano-fabrication technique can be used to create <span class="hlt">electronic</span> devices which are based upon complex arrangements of nanocrystals. Finally, the fabrication and electrical characterization of a nanocrystal-based single <span class="hlt">electron</span> transistor is presented. This device is fabricated using a hybrid scheme which combines <span class="hlt">electron</span> beam lithography and wet chemistry to bind single nanocrystals in tunneling contact between closely spaced metallic leads. In these devices, both Au and CdSe nanocrystals show Coulomb blockade effects with characteristic energies of several tens of meV. Additional structure is seen the <span class="hlt">transport</span> behavior of CdSe nanocrystals as a result of its <span class="hlt">electronic</span> structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22218426','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218426"><span id="translatedtitle">Turbulent <span class="hlt">electron</span> <span class="hlt">transport</span> in edge pedestal by <span class="hlt">electron</span> temperature gradient turbulence</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Singh, R.; Jhang, Hogun; Diamond, P. H.</p> <p>2013-11-15</p> <p>We present a model for turbulent <span class="hlt">electron</span> thermal <span class="hlt">transport</span> at the edge pedestal in high (H)-mode plasmas based on <span class="hlt">electron</span> temperature gradient (ETG) turbulence. A quasi-linear analysis of electrostatic toroidal ETG modes shows that both turbulent <span class="hlt">electron</span> thermal diffusivity and hyper-resistivity exhibits the Ohkawa scaling in which the radial correlation length of turbulence becomes the order of <span class="hlt">electron</span> skin depth. Combination of the Ohkawa scales and the plasma current dependence results in a novel confinement scaling inside the pedestal region. It is also shown that ETG turbulence induces a thermoelectric pinch, which may accelerate the density pedestal formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.2989R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.2989R"><span id="translatedtitle">Solar flare accelerated <span class="hlt">electron</span> <span class="hlt">transport</span> through the turbulent solar wind</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reid, Hamish; Kontar, Eduard</p> <p></p> <p>Solar flare accelerated <span class="hlt">electron</span> beams can become unstable during <span class="hlt">transport</span> from the Sun to the Earth, producing plasma waves in the turbulent inner heliosphere. We simulate solar <span class="hlt">electron</span> beam propagation to the Earth in the weak turbulent regime taking into account the self-consistent generation of plasma waves. Induced plasma waves interact with the density fluctuations from low frequency MHD turbulence present in the background plasma. These fluctuations act to suppress the generation of waves, most acutely when fluctuations have large amplitudes or small wavelengths. The reduction of plasma wave generation alters the wave distribution which changes <span class="hlt">electron</span> beam <span class="hlt">transport</span>. Assuming an observed 5/3 Kolmogorov-type power density spectra of fluctuations, we investigate the energy spectra of the <span class="hlt">electron</span> beam near the Earth. We find the presence of turbulence in the background plasma alters the spectral index below the break energy of the double power-law formed at 1AU. From an initial single power-law <span class="hlt">electron</span> distribution, we find a range of spectra below the break energy, with higher levels of turbulence corresponding to a higher spectral index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20860240','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20860240"><span id="translatedtitle">Nonlocal <span class="hlt">electron</span> <span class="hlt">transport</span> in magnetized plasmas with arbitrary atomic number</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bennaceur-Doumaz, D.; Bendib, A.</p> <p>2006-09-15</p> <p>The numerical solution of the steady-state <span class="hlt">electron</span> Fokker-Planck equation perturbed with respect to a global equilibrium is presented in magnetized plasmas with arbitrary atomic number Z. The magnetic field is assumed to be constant and the <span class="hlt">electron-electron</span> collisions are described by the Landau collision operator. The solution is derived in the Fourier space and in the framework of the diffusive approximation which captures the spatial nonlocal effects. The <span class="hlt">transport</span> coefficients are deduced and used to close a complete set of nonlocal <span class="hlt">electron</span> fluid equations. This work improves the results of A. Bendib et al. [Phys. Plasmas 9, 1555 (2002)] and of A. V. Brantov et al. [Phys. Plasmas 10, 4633 (2003)] restricted to the local and nonlocal high-Z plasma approximations, respectively. The influence of the magnetic field on the nonlocal effects is discussed. We propose also accurate numerical fits of the relevant <span class="hlt">transport</span> coefficients with respect to the collisionality parameter {lambda}{sub ei}/L and the atomic number Z, where L is the typical scale length and {lambda}{sub ei} is the <span class="hlt">electron</span>-ion mean-free-path.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/46558','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/46558"><span id="translatedtitle">Adjoint <span class="hlt">electron</span>-photon <span class="hlt">transport</span> Monte Carlo calculations with ITS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lorence, L.J.; Kensek, R.P.; Halbleib, J.A.; Morel, J.E.</p> <p>1995-02-01</p> <p>A general adjoint coupled <span class="hlt">electron</span>-photon Monte Carlo code for solving the Boltzmann-Fokker-Planck equation has recently been created. It is a modified version of ITS 3.0, a coupled electronphoton Monte Carlo code that has world-wide distribution. The applicability of the new code to radiation-interaction problems of the type found in space <span class="hlt">environments</span> is demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007APS..MARL31012D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007APS..MARL31012D"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">Transport</span> and Tunneling in Single Walled Carbon Nanotube Devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dirks, Travis; Mason, Nadya</p> <p>2007-03-01</p> <p>Carbon nanotubes remain a fertile ground for the exploration of interacting one-dimensional (1D) physics and Tomonaga-Luttinger liquid theory. Much is still unknown about the factors that influence the <span class="hlt">transport</span> and tunneling properties of interacting 1D systems such as nanotubes. We report on experiments that use techniques such as multiple contacts on long nanotubes and tunable tunnel barriers to determine how the manifestations of <span class="hlt">electron-electron</span> interactions, such as the zero-bias anomaly, depend on the length and defect strength in nanotubes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.108j3502C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.108j3502C"><span id="translatedtitle"><span class="hlt">Transport</span> in organic single-crystal microbelt for conformal <span class="hlt">electronics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cui, Nan; Tong, Yanhong; Tang, Qingxin; Liu, Yichun</p> <p>2016-03-01</p> <p>We showed the advantages of flexible rubrene organic single-crystal microbelts in high-performance devices and circuits towards conformal <span class="hlt">electronics</span>. The anisotropic <span class="hlt">transport</span> based on the only one organic microbelt was studied by a "cross-channel" method, and the rubrene microbelt showed the highest mobility up to 26 cm2/V s in the length direction. Based on an individual rubrene microbelt, the organic single-crystal circuit with good adherence on a pearl ball and the gain as high as 18 was realized. These results present great potential for applications of organic single-crystal belts in the next-generation conformal <span class="hlt">electronics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatCo...711381B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCo...711381B"><span id="translatedtitle">Nanoscale <span class="hlt">electron</span> <span class="hlt">transport</span> at the surface of a topological insulator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bauer, Sebastian; Bobisch, Christian A.</p> <p>2016-04-01</p> <p>The use of three-dimensional topological insulators for disruptive technologies critically depends on the dissipationless <span class="hlt">transport</span> of <span class="hlt">electrons</span> at the surface, because of the suppression of backscattering at defects. However, in real devices, defects are unavoidable and scattering at angles other than 180° is allowed for such materials. Until now, this has been studied indirectly by bulk measurements and by the analysis of the local density of states in close vicinity to defect sites. Here, we directly measure the nanoscale voltage drop caused by the scattering at step edges, which occurs if a lateral current flows along a three-dimensional topological insulator. The experiments were performed using scanning tunnelling potentiometry for thin Bi2Se3 films. So far, the observed voltage drops are small because of large contributions of the bulk to the <span class="hlt">electronic</span> <span class="hlt">transport</span>. However, for the use of ideal topological insulating thin films in devices, these contributions would play a significant role.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4844676','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4844676"><span id="translatedtitle">Nanoscale <span class="hlt">electron</span> <span class="hlt">transport</span> at the surface of a topological insulator</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bauer, Sebastian; Bobisch, Christian A.</p> <p>2016-01-01</p> <p>The use of three-dimensional topological insulators for disruptive technologies critically depends on the dissipationless <span class="hlt">transport</span> of <span class="hlt">electrons</span> at the surface, because of the suppression of backscattering at defects. However, in real devices, defects are unavoidable and scattering at angles other than 180° is allowed for such materials. Until now, this has been studied indirectly by bulk measurements and by the analysis of the local density of states in close vicinity to defect sites. Here, we directly measure the nanoscale voltage drop caused by the scattering at step edges, which occurs if a lateral current flows along a three-dimensional topological insulator. The experiments were performed using scanning tunnelling potentiometry for thin Bi2Se3 films. So far, the observed voltage drops are small because of large contributions of the bulk to the <span class="hlt">electronic</span> <span class="hlt">transport</span>. However, for the use of ideal topological insulating thin films in devices, these contributions would play a significant role. PMID:27098939</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21537874','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21537874"><span id="translatedtitle"><span class="hlt">Electron</span> heat <span class="hlt">transport</span> from stochastic fields in gyrokinetic simulations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, E.; Nevins, W. M.; Candy, J.; Hatch, D.; Terry, P.; Guttenfelder, W.</p> <p>2011-05-15</p> <p>GYRO is used to examine the perturbed magnetic field structure generated by electromagnetic gyrokinetic simulations of the CYCLONE base case as {beta}{sub e} is varied from 0.1% to 0.7%, as investigated by J. Candy [Phys. Plasmas 12, 072307 (2005)]. Poincare surface of section plots obtained from integrating the self-consistent magnetic field demonstrates widespread stochasticity for all nonzero values of {beta}{sub e}. Despite widespread stochasticity of the perturbed magnetic fields, no significant increase in <span class="hlt">electron</span> <span class="hlt">transport</span> is observed. The magnetic diffusion, d{sub m}[A. B. Rechester and M. N. Rosenbluth, Phys. Rev. Lett 40, 38 (1978)], is used to quantify the degree of stochasticity and related to the <span class="hlt">electron</span> heat <span class="hlt">transport</span> for hundreds of time slices in each simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5551451','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5551451"><span id="translatedtitle">Two-point model for <span class="hlt">electron</span> <span class="hlt">transport</span> in EBT</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chiu, S.C.; Guest, G.E.</p> <p>1980-01-01</p> <p>The <span class="hlt">electron</span> <span class="hlt">transport</span> in EBT is simulated by a two-point model corresponding to the central plasma and the edge. The central plasma is assumed to obey neoclassical collisionless <span class="hlt">transport</span>. The edge plasma is assumed turbulent and modeled by Bohm diffusion. The steady-state temperatures and densities in both regions are obtained as functions of neutral influx and microwave power. It is found that as the neutral influx decreases and power increases, the edge density decreases while the core density increases. We conclude that if ring instability is responsible for the T-M mode transition, and if stability is correlated with cold <span class="hlt">electron</span> density at the edge, it will depend sensitively on ambient gas pressure and microwave power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARA22005M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARA22005M"><span id="translatedtitle">Ab Initio <span class="hlt">Electronic</span> Relaxation Times and <span class="hlt">Transport</span> in Noble Metals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mustafa, Jamal I.; Bernardi, Marco; Neaton, Jeffrey B.; Louie, Steven G.</p> <p></p> <p>Relaxation times employed to study <span class="hlt">electron</span> <span class="hlt">transport</span> in metals are typically assumed to be constants and obtained empirically using the Drude model. Here, we employ ab initio calculations to compute the <span class="hlt">electron</span>-phonon relaxation times of Cu, Ag, and Au, and find that they vary significantly on the Fermi surface, spanning ~15 -45 fs. We compute room temperature resistivities in excellent agreement with experiment by combining GW bandstructures, Wannier-interpolated band velocities, and ab initio relaxation times. Our calculations are compared to other approximations used for the relaxation times. Additionally, an importance sampling scheme is introduced to speed up the convergence of resistivity and <span class="hlt">transport</span> calculations by sampling directly points on the Fermi surface. This work was supported by NSF Grant No. DMR15-1508412 and U.S. DOE under Contract No. DE-AC02-05CH11231. Computational resources have been provided by DOE at LBNL's NERSC facility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhPl...18e6111W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhPl...18e6111W"><span id="translatedtitle"><span class="hlt">Electron</span> heat <span class="hlt">transport</span> from stochastic fields in gyrokinetic simulationsa)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, E.; Nevins, W. M.; Candy, J.; Hatch, D.; Terry, P.; Guttenfelder, W.</p> <p>2011-05-01</p> <p>GYRO is used to examine the perturbed magnetic field structure generated by electromagnetic gyrokinetic simulations of the CYCLONE base case as βe is varied from 0.1% to 0.7%, as investigated by J. Candy [Phys. Plasmas 12, 072307 (2005)]. Poincare surface of section plots obtained from integrating the self-consistent magnetic field demonstrates widespread stochasticity for all nonzero values of βe. Despite widespread stochasticity of the perturbed magnetic fields, no significant increase in <span class="hlt">electron</span> <span class="hlt">transport</span> is observed. The magnetic diffusion, dm [A. B. Rechester and M. N. Rosenbluth, Phys. Rev. Lett 40, 38 (1978)], is used to quantify the degree of stochasticity and related to the <span class="hlt">electron</span> heat <span class="hlt">transport</span> for hundreds of time slices in each simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JAP...114f3304H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JAP...114f3304H"><span id="translatedtitle"><span class="hlt">Transport</span> of <span class="hlt">electron</span> beams with initial transverse-longitudinal correlation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harris, J. R.; Lewellen, J. W.; Poole, B. R.</p> <p>2013-08-01</p> <p>When an <span class="hlt">electron</span> beam whose current varies in time is extracted from a DC gun, the competition between the time-dependent space charge force and the time-independent focusing force will cause a correlation between radius, divergence, current, and position along the beam. This correlation will determine the beam's configuration in trace space, and together with the design of the downstream <span class="hlt">transport</span> system, will determine the quality of the <span class="hlt">transport</span> solutions that can be obtained, including the amplitude of the mismatch oscillations occurring in each slice of the beam. Recent simulations of a simplified diode with Pierce-type focusing operating at nonrelativistic voltages indicated that the radius and divergence of beams extracted from such guns can be approximated to high accuracy as linear functions of current. Here, we consider the impact of this dependence on the beam configuration in trace space and investigate the implications for matching and <span class="hlt">transport</span> of such correlated beams in uniform linear focusing channels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/532581','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/532581"><span id="translatedtitle">Status of <span class="hlt">electron</span> <span class="hlt">transport</span> in MCNP{trademark}</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hughes, H.G.</p> <p>1997-09-01</p> <p>The latest version of MCNP, the Los Alamos Monte Carlo <span class="hlt">transport</span> code, has now been officially released. MCNP4B has been sent to the Radiation Safety Information Computational Center (RSICC), in Oak Ridge, Tennessee, which is responsible for the further distribution of the code within the US. International distribution of MCNP is done by the Nuclear Energy Agency (ECD/NEA), in Paris, France. Readers with access to the World-Wide-Web should consult the MCNP distribution site http://www-xdiv.lanl.gov/XTM/mcnp/about.html for specific information about contacting RSICC and OECD/NEA. A variety of new features are available in MCNP4B. Among these are differential operator perturbations, cross-section plotting capabilities, enhanced diagnostics for <span class="hlt">transport</span> in repeated structures and lattices, improved efficiency in distributed-memory multiprocessing, corrected particle lifetime and lifespan estimators, and expanded software quality assurance procedures and testing, including testing of the multigroup Boltzmann-Fokker-Planck capability. New and improved cross section sets in the form of ENDF/B-VI evaluations have also been recently released and can be used in MCNP4B. Perhaps most significant for the interests of this special session, the <span class="hlt">electron</span> <span class="hlt">transport</span> algorithm has been improved, especially in the collisional energy-loss straggling and the angular-deflection treatments. In this paper, the author concentrates on a fairly complete documentation of the current status of the <span class="hlt">electron</span> <span class="hlt">transport</span> methods in MCNP.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030016689','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030016689"><span id="translatedtitle"><span class="hlt">Electronic</span> Components and Circuits for Extreme Temperature <span class="hlt">Environments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Patterson, Richard L.; Hammoud, Ahmad; Dickman, John E.; Gerber, Scott</p> <p>2003-01-01</p> <p>Planetary exploration missions and deep space probes require electrical power management and control systems that are capable of efficient and reliable operation in very low temperature <span class="hlt">environments</span>. Presently, spacecraft operating in the cold <span class="hlt">environment</span> of deep space carry a large number of radioisotope heating units in order to maintain the surrounding temperature of the on-board <span class="hlt">electronics</span> at approximately 20 C. <span class="hlt">Electronics</span> capable of operation at cryogenic temperatures will not only tolerate the hostile <span class="hlt">environment</span> of deep space but also reduce system size and weight by eliminating or reducing the radioisotope heating units and their associate structures; thereby reducing system development as well as launch costs. In addition, power <span class="hlt">electronic</span> circuits designed for operation at low temperatures are expected to result in more efficient systems than those at room temperature. This improvement results from better behavior and tolerance in the electrical and thermal properties of semiconductor and dielectric materials at low temperatures. The Low Temperature <span class="hlt">Electronics</span> Program at the NASA Glenn Research Center focuses on research and development of electrical components, circuits, and systems suitable for applications in the aerospace <span class="hlt">environment</span> and deep space exploration missions. Research is being conducted on devices and systems for reliable use down to cryogenic temperatures. Some of the commercial-off-the-shelf as well as developed components that are being characterized include switching devices, resistors, magnetics, and capacitors. Semiconductor devices and integrated circuits including digital-to-analog and analog-to-digital converters, DC/DC converters, operational amplifiers, and oscillators are also being investigated for potential use in low temperature applications. An overview of the NASA Glenn Research Center Low Temperature <span class="hlt">Electronic</span> Program will be presented in this paper. A description of the low temperature test facilities along with</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22415564','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22415564"><span id="translatedtitle">The role of <span class="hlt">electron</span>-impact vibrational excitation in <span class="hlt">electron</span> <span class="hlt">transport</span> through gaseous tetrahydrofuran</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Duque, H. V.; Do, T. P. T.; Konovalov, D. A.; White, R. D.; Brunger, M. J. E-mail: darryl.jones@flinders.edu.au; Jones, D. B. E-mail: darryl.jones@flinders.edu.au</p> <p>2015-03-28</p> <p>In this paper, we report newly derived integral cross sections (ICSs) for <span class="hlt">electron</span> impact vibrational excitation of tetrahydrofuran (THF) at intermediate impact energies. These cross sections extend the currently available data from 20 to 50 eV. Further, they indicate that the previously recommended THF ICS set [Garland et al., Phys. Rev. A 88, 062712 (2013)] underestimated the strength of the <span class="hlt">electron</span>-impact vibrational excitation processes. Thus, that recommended vibrational cross section set is revised to address those deficiencies. <span class="hlt">Electron</span> swarm <span class="hlt">transport</span> properties were calculated with the amended vibrational cross section set, to quantify the role of <span class="hlt">electron</span>-driven vibrational excitation in describing the macroscopic swarm phenomena. Here, significant differences of up to 17% in the <span class="hlt">transport</span> coefficients were observed between the calculations performed using the original and revised cross section sets for vibrational excitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhDT.......149T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhDT.......149T"><span id="translatedtitle">Charge <span class="hlt">transport</span> and injection in amorphous organic <span class="hlt">electronic</span> materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tse, Shing Chi</p> <p></p> <p>This thesis presents how we use various measuring techniques to study the charge <span class="hlt">transport</span> and injection in organic <span class="hlt">electronic</span> materials. Understanding charge <span class="hlt">transport</span> and injection properties in organic solids is of vital importance for improving performance characteristics of organic <span class="hlt">electronic</span> devices, including organic-light-emitting diodes (OLEDs), photovoltaic cells (OPVs), and field effect transistors (OFETs). The charge <span class="hlt">transport</span> properties of amorphous organic materials, commonly used in organic <span class="hlt">electronic</span> devices, are investigated by the means of carrier mobility measurements. Transient electroluminescence (EL) technique was used to evaluate the <span class="hlt">electron</span> mobility of an <span class="hlt">electron</span> <span class="hlt">transporting</span> material--- tris(8-hydroxyquinoline) aluminum (Alq3). The results are in excellent agreement with independent time-of-flight (TOF) measurements. Then, the effect of dopants on <span class="hlt">electron</span> <span class="hlt">transport</span> was also examined. TOF technique was also used to examine the effects of tertiary-butyl (t-Bu) substitutions on anthracene derivatives (ADN). All ADN compounds were found to be ambipolar. As the degree of t-Bu substitution increases, the carrier mobilities decrease progressively. The reduction of carrier mobilities with increasing t-butylation can be attributed to a decrease in the charge-transfer integral or the wavefunction overlap. In addition, from TOF measurements, two naphthylamine-based hole <span class="hlt">transporters</span>, namely, N,N'-diphenyl-N,N'-bis(1-naphthyl)(1,1'-biphenyl)-4,4'diamine (NPB) and 4,4',4"-tris(n-(2-naphthyl)-n-phenyl-amino)-triphenylamine (2TNATA) were found to possess <span class="hlt">electron-transporting</span> (ET) abilities. An organic light-emitting diode that employed NPB as the ET material was demonstrated. The <span class="hlt">electron</span> conducting mechanism of NPB and 2TNATA in relation to the hopping model will be discussed. Furthermore, the ET property of NPB applied in OLEDs will also be examined. Besides transient EL and TOF techniques, we also use dark-injection space-charge-limited current</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22486307','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22486307"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> in VO{sub 2}—Experimentally calibrated Boltzmann <span class="hlt">transport</span> modeling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kinaci, Alper; Rosenmann, Daniel; Chan, Maria K. Y. E-mail: mchan@anl.gov; Kado, Motohisa; Ling, Chen; Zhu, Gaohua; Banerjee, Debasish E-mail: mchan@anl.gov</p> <p>2015-12-28</p> <p>Materials that undergo metal-insulator transitions (MITs) are under intense study, because the transition is scientifically fascinating and technologically promising for various applications. Among these materials, VO{sub 2} has served as a prototype due to its favorable transition temperature. While the physical underpinnings of the transition have been heavily investigated experimentally and computationally, quantitative modeling of <span class="hlt">electronic</span> <span class="hlt">transport</span> in the two phases has yet to be undertaken. In this work, we establish a density-functional-theory (DFT)-based approach with Hubbard U correction (DFT + U) to model <span class="hlt">electronic</span> <span class="hlt">transport</span> properties in VO{sub 2} in the semiconducting and metallic regimes, focusing on band <span class="hlt">transport</span> using the Boltzmann <span class="hlt">transport</span> equations. We synthesized high quality VO{sub 2} films and measured the <span class="hlt">transport</span> quantities across the transition, in order to calibrate the free parameters in the model. We find that the experimental calibration of the Hubbard correction term can efficiently and adequately model the metallic and semiconducting phases, allowing for further computational design of MIT materials for desirable <span class="hlt">transport</span> properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25909689','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25909689"><span id="translatedtitle">Theoretical investigations into the <span class="hlt">electronic</span> structures and <span class="hlt">electron</span> <span class="hlt">transport</span> properties of fluorine and carbonyl end-functionalized quarterthiophenes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Qian; Duan, Yuai; Gao, Hong-Ze; Su, Zhong-Мin; Geng, Yun</p> <p>2015-06-01</p> <p>In this work, we concentrate on systematic investigation on the fluorination and carbonylation effect on <span class="hlt">electron</span> <span class="hlt">transport</span> properties of thiophene-based materials with the aim of seeking and designing <span class="hlt">electron</span> <span class="hlt">transport</span> materials. Some relative factors, namely, frontier molecular orbital (FMO), vertical <span class="hlt">electron</span> affinity (VEA), <span class="hlt">electron</span> reorganization energy (λele), <span class="hlt">electron</span> transfer integral (tele), <span class="hlt">electron</span> drift mobility (μele) and band structures have been calculated and discussed based on density functional theory. The results show that the introduction of fluorine atoms and carbonyl group especially for the latter could effectively increase EA and reduce λele, which is beneficial to the improvement of <span class="hlt">electron</span> <span class="hlt">transport</span> performance. Furthermore, these introductions could also affect the tele by changing molecular packing manner and distribution of FMO. Finally, according to our calculation, the 3d system is considered to be a promising <span class="hlt">electron</span> <span class="hlt">transport</span> material with small λele, high <span class="hlt">electron</span> <span class="hlt">transport</span> ability and good ambient stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25909689','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25909689"><span id="translatedtitle">Theoretical investigations into the <span class="hlt">electronic</span> structures and <span class="hlt">electron</span> <span class="hlt">transport</span> properties of fluorine and carbonyl end-functionalized quarterthiophenes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Qian; Duan, Yuai; Gao, Hong-Ze; Su, Zhong-Мin; Geng, Yun</p> <p>2015-06-01</p> <p>In this work, we concentrate on systematic investigation on the fluorination and carbonylation effect on <span class="hlt">electron</span> <span class="hlt">transport</span> properties of thiophene-based materials with the aim of seeking and designing <span class="hlt">electron</span> <span class="hlt">transport</span> materials. Some relative factors, namely, frontier molecular orbital (FMO), vertical <span class="hlt">electron</span> affinity (VEA), <span class="hlt">electron</span> reorganization energy (λele), <span class="hlt">electron</span> transfer integral (tele), <span class="hlt">electron</span> drift mobility (μele) and band structures have been calculated and discussed based on density functional theory. The results show that the introduction of fluorine atoms and carbonyl group especially for the latter could effectively increase EA and reduce λele, which is beneficial to the improvement of <span class="hlt">electron</span> <span class="hlt">transport</span> performance. Furthermore, these introductions could also affect the tele by changing molecular packing manner and distribution of FMO. Finally, according to our calculation, the 3d system is considered to be a promising <span class="hlt">electron</span> <span class="hlt">transport</span> material with small λele, high <span class="hlt">electron</span> <span class="hlt">transport</span> ability and good ambient stability. PMID:25909689</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080032798','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080032798"><span id="translatedtitle">Technology Developments in Radiation-Hardened <span class="hlt">Electronics</span> for Space <span class="hlt">Environments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Keys, Andrew S.; Howell, Joe T.</p> <p>2008-01-01</p> <p>The Radiation Hardened <span class="hlt">Electronics</span> for Space <span class="hlt">Environments</span> (RHESE) project consists of a series of tasks designed to develop and mature a broad spectrum of radiation hardened and low temperature <span class="hlt">electronics</span> technologies. Three approaches are being taken to address radiation hardening: improved material hardness, design techniques to improve radiation tolerance, and software methods to improve radiation tolerance. Within these approaches various technology products are being addressed including Field Programmable Gate Arrays (FPGA), Field Programmable Analog Arrays (FPAA), MEMS, Serial Processors, Reconfigurable Processors, and Parallel Processors. In addition to radiation hardening, low temperature extremes are addressed with a focus on material and design approaches. System level applications for the RHESE technology products are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatSR...4E5983J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatSR...4E5983J"><span id="translatedtitle">Energy level control: toward an efficient hot <span class="hlt">electron</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Xiao; Li, Qinghua; Li, Yue; Chen, Zihan; Wei, Tai-Huei; He, Xingdao; Sun, Weifu</p> <p>2014-08-01</p> <p>Highly efficient hot <span class="hlt">electron</span> <span class="hlt">transport</span> represents one of the most important properties required for applications in photovoltaic devices. Whereas the fabrication of efficient hot <span class="hlt">electron</span> capture and lost-cost devices remains a technological challenge, regulating the energy level of acceptor-donor system through the incorporation of foreign ions using the solution-processed technique is one of the most promising strategies to overcome this obstacle. Here we present a versatile acceptor-donor system by incorporating MoO3:Eu nanophosphors, which reduces both the `excess' energy offset between the conduction band of acceptor and the lowest unoccupied molecular orbital of donor, and that between the valence band and highest occupied molecular orbital. Strikingly, the hot <span class="hlt">electron</span> transfer time has been shortened. This work demonstrates that suitable energy level alignment can be tuned to gain the higher hot <span class="hlt">electron</span>/hole <span class="hlt">transport</span> efficiency in a simple approach without the need for complicated architectures. This work builds up the foundation of engineering building blocks for third-generation solar cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25099864','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25099864"><span id="translatedtitle">Energy level control: toward an efficient hot <span class="hlt">electron</span> <span class="hlt">transport</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jin, Xiao; Li, Qinghua; Li, Yue; Chen, Zihan; Wei, Tai-Huei; He, Xingdao; Sun, Weifu</p> <p>2014-08-07</p> <p>Highly efficient hot <span class="hlt">electron</span> <span class="hlt">transport</span> represents one of the most important properties required for applications in photovoltaic devices. Whereas the fabrication of efficient hot <span class="hlt">electron</span> capture and lost-cost devices remains a technological challenge, regulating the energy level of acceptor-donor system through the incorporation of foreign ions using the solution-processed technique is one of the most promising strategies to overcome this obstacle. Here we present a versatile acceptor-donor system by incorporating MoO3:Eu nanophosphors, which reduces both the 'excess' energy offset between the conduction band of acceptor and the lowest unoccupied molecular orbital of donor, and that between the valence band and highest occupied molecular orbital. Strikingly, the hot <span class="hlt">electron</span> transfer time has been shortened. This work demonstrates that suitable energy level alignment can be tuned to gain the higher hot <span class="hlt">electron</span>/hole <span class="hlt">transport</span> efficiency in a simple approach without the need for complicated architectures. This work builds up the foundation of engineering building blocks for third-generation solar cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24132041','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24132041"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> through a quantum dot assisted by cavity photons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abdullah, Nzar Rauf; Tang, Chi-Shung; Manolescu, Andrei; Gudmundsson, Vidar</p> <p>2013-11-20</p> <p>We investigate transient <span class="hlt">transport</span> of <span class="hlt">electrons</span> through a single quantum dot controlled by a plunger gate. The dot is embedded in a finite wire with length Lx assumed to lie along the x-direction with a parabolic confinement in the y-direction. The quantum wire, originally with hard-wall confinement at its ends, ±Lx/2, is weakly coupled at t = 0 to left and right leads acting as external <span class="hlt">electron</span> reservoirs. The central system, the dot and the finite wire, is strongly coupled to a single cavity photon mode. A non-Markovian density-matrix formalism is employed to take into account the full <span class="hlt">electron</span>-photon interaction in the transient regime. In the absence of a photon cavity, a resonant current peak can be found by tuning the plunger-gate voltage to lift a many-body state of the system into the source-drain bias window. In the presence of an x-polarized photon field, additional side peaks can be found due to photon-assisted <span class="hlt">transport</span>. By appropriately tuning the plunger-gate voltage, the <span class="hlt">electrons</span> in the left lead are allowed to undergo coherent inelastic scattering to a two-photon state above the bias window if initially one photon was present in the cavity. However, this photon-assisted feature is suppressed in the case of a y-polarized photon field due to the anisotropy of our system caused by its geometry. PMID:24132041</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26838371','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26838371"><span id="translatedtitle">Control of <span class="hlt">electronic</span> <span class="hlt">transport</span> in graphene by electromagnetic dressing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kristinsson, K; Kibis, O V; Morina, S; Shelykh, I A</p> <p>2016-01-01</p> <p>We demonstrated theoretically that the renormalization of the <span class="hlt">electron</span> energy spectrum near the Dirac point of graphene by a strong high-frequency electromagnetic field (dressing field) drastically depends on polarization of the field. Namely, linear polarization results in an anisotropic gapless energy spectrum, whereas circular polarization leads to an isotropic gapped one. As a consequence, the stationary (dc) <span class="hlt">electronic</span> <span class="hlt">transport</span> in graphene strongly depends on parameters of the dressing field: A circularly polarized field monotonically decreases the isotropic conductivity of graphene, whereas a linearly polarized one results in both giant anisotropy of conductivity (which can reach thousands of percents) and the oscillating behavior of the conductivity as a function of the field intensity. Since the predicted phenomena can be observed in a graphene layer irradiated by a monochromatic electromagnetic wave, the elaborated theory opens a substantially new way to control <span class="hlt">electronic</span> properties of graphene with light. PMID:26838371</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4738282','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4738282"><span id="translatedtitle">Control of <span class="hlt">electronic</span> <span class="hlt">transport</span> in graphene by electromagnetic dressing</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kristinsson, K.; Kibis, O. V.; Morina, S.; Shelykh, I. A.</p> <p>2016-01-01</p> <p>We demonstrated theoretically that the renormalization of the <span class="hlt">electron</span> energy spectrum near the Dirac point of graphene by a strong high-frequency electromagnetic field (dressing field) drastically depends on polarization of the field. Namely, linear polarization results in an anisotropic gapless energy spectrum, whereas circular polarization leads to an isotropic gapped one. As a consequence, the stationary (dc) <span class="hlt">electronic</span> <span class="hlt">transport</span> in graphene strongly depends on parameters of the dressing field: A circularly polarized field monotonically decreases the isotropic conductivity of graphene, whereas a linearly polarized one results in both giant anisotropy of conductivity (which can reach thousands of percents) and the oscillating behavior of the conductivity as a function of the field intensity. Since the predicted phenomena can be observed in a graphene layer irradiated by a monochromatic electromagnetic wave, the elaborated theory opens a substantially new way to control <span class="hlt">electronic</span> properties of graphene with light. PMID:26838371</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PPCF...51l4035P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PPCF...51l4035P"><span id="translatedtitle">Fast-<span class="hlt">electron</span> <span class="hlt">transport</span> in cylindrically laser-compressed matter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perez, F.; Koenig, M.; Batani, D.; Baton, S. D.; Beg, F. N.; Benedetti, C.; Brambrink, E.; Chawla, S.; Dorchies, F.; Fourment, C.; Galimberti, M.; Gizzi, L. A.; Heathcote, R.; Higginson, D. P.; Hulin, S.; Jafer, R.; Koester, P.; Labate, L.; Lancaster, K.; Mac Kinnon, A. J.; McPhee, A. G.; Nazarov, W.; Nicolai, P.; Pasley, J.; Ravasio, A.; Richetta, M.; Santos, J. J.; Sgattoni, A.; Spindloe, C.; Vauzour, B.; Volpe, L.</p> <p>2009-12-01</p> <p>Experimental and theoretical results of relativistic <span class="hlt">electron</span> <span class="hlt">transport</span> in cylindrically compressed matter are presented. This experiment, which is a part of the HiPER roadmap, was achieved on the VULCAN laser facility (UK) using four long pulses beams (~4 × 50 J, 1 ns, at 0.53 µm) to compress a hollow plastic cylinder filled with plastic foam of three different densities (0.1, 0.3 and 1 g cm-3). 2D simulations predict a density of 2-5 g cm-3 and a plasma temperature up to 100 eV at maximum compression. A short pulse (10 ps, 160 J) beam generated fast <span class="hlt">electrons</span> that propagate through the compressed matter by irradiating a nickel foil at an intensity of 5 × 1018 W cm-2. X-ray spectrometer and imagers were implemented in order to estimate the compressed plasma conditions and to infer the hot <span class="hlt">electron</span> characteristics. Results are discussed and compared with simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...620082K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...620082K"><span id="translatedtitle">Control of <span class="hlt">electronic</span> <span class="hlt">transport</span> in graphene by electromagnetic dressing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kristinsson, K.; Kibis, O. V.; Morina, S.; Shelykh, I. A.</p> <p>2016-02-01</p> <p>We demonstrated theoretically that the renormalization of the <span class="hlt">electron</span> energy spectrum near the Dirac point of graphene by a strong high-frequency electromagnetic field (dressing field) drastically depends on polarization of the field. Namely, linear polarization results in an anisotropic gapless energy spectrum, whereas circular polarization leads to an isotropic gapped one. As a consequence, the stationary (dc) <span class="hlt">electronic</span> <span class="hlt">transport</span> in graphene strongly depends on parameters of the dressing field: A circularly polarized field monotonically decreases the isotropic conductivity of graphene, whereas a linearly polarized one results in both giant anisotropy of conductivity (which can reach thousands of percents) and the oscillating behavior of the conductivity as a function of the field intensity. Since the predicted phenomena can be observed in a graphene layer irradiated by a monochromatic electromagnetic wave, the elaborated theory opens a substantially new way to control <span class="hlt">electronic</span> properties of graphene with light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26838371','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26838371"><span id="translatedtitle">Control of <span class="hlt">electronic</span> <span class="hlt">transport</span> in graphene by electromagnetic dressing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kristinsson, K; Kibis, O V; Morina, S; Shelykh, I A</p> <p>2016-02-03</p> <p>We demonstrated theoretically that the renormalization of the <span class="hlt">electron</span> energy spectrum near the Dirac point of graphene by a strong high-frequency electromagnetic field (dressing field) drastically depends on polarization of the field. Namely, linear polarization results in an anisotropic gapless energy spectrum, whereas circular polarization leads to an isotropic gapped one. As a consequence, the stationary (dc) <span class="hlt">electronic</span> <span class="hlt">transport</span> in graphene strongly depends on parameters of the dressing field: A circularly polarized field monotonically decreases the isotropic conductivity of graphene, whereas a linearly polarized one results in both giant anisotropy of conductivity (which can reach thousands of percents) and the oscillating behavior of the conductivity as a function of the field intensity. Since the predicted phenomena can be observed in a graphene layer irradiated by a monochromatic electromagnetic wave, the elaborated theory opens a substantially new way to control <span class="hlt">electronic</span> properties of graphene with light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999PhDT.......165H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999PhDT.......165H&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> and dephasing in semiconductor quantum dots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huibers, Andrew Gerrit A.</p> <p></p> <p>At low temperatures, <span class="hlt">electrons</span> in semiconductors can be phase coherent over distances exceeding tens of microns and are sufficiently monochromatic that a variety of interesting quantum interference phenomena can be observed and manipulated. This work discusses <span class="hlt">electron</span> <span class="hlt">transport</span> measurements through cavities (quantum dots) formed by laterally confining <span class="hlt">electrons</span> in the two-dimensional sub-band of a GaAs/AlGaAs heterojunction. Metal gates fabricated using e-beam lithography enable fine control of the cavity shape as well as the leads which connect the dot cavity to source and drain reservoirs. Quantum dots can be modeled by treating the devices as chaotic scatterers. Predictions of this theoretical description are found to be in good quantitative agreement with experimental measurements of full conductance distributions at different temperatures. Weak localization, the suppression of conductance due to phase-coherent backscattering at zero magnetic field, is used to measure dephasing times in the system. Mechanisms responsible for dephasing, including <span class="hlt">electron-electron</span> scattering and Nyquist phase relaxation, are investigated by studying the loss of phase coherence as a function of temperature. Coupling of external microwave fields to the device is also studied to shed light on the unexpected saturation of dephasing that is observed below an <span class="hlt">electron</span> temperature of 100 mK. The effect of external fields in the present experiment is explained in terms of Joule heating from an ac bias.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21506911','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21506911"><span id="translatedtitle">Energetic <span class="hlt">Electron</span> <span class="hlt">Transport</span> In An Inhomogeneous Plasma Medium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Das, Amita</p> <p>2010-11-23</p> <p>A review of the work carried out at IPR on energetic <span class="hlt">electron</span> <span class="hlt">transport</span> through an inhomogeneous plasma medium is presented in this article. A Generalized <span class="hlt">Electron</span> Magnetohydrodynamic (G-EMHD) fluid model has been developed and employed for such studies. Novel observations such as (i) the trapping of <span class="hlt">electron</span> current pulse structure in a high density plasma region, (ii) the formation of sharp magnetic field shock structures at the inhomogeneous plasma density layer (iii) and intense energy dissipation at the shock layer even in the collisionless limit are reported. The intense energy dissipation of the <span class="hlt">electron</span> current pulse at the shock layer provides a mechanism whereby highly energetic <span class="hlt">electrons</span> which are essentially collision-less can also successfully deposit their energy in a local region of the plasma. This is specially attractive as it opens up the possibility of heating a localized region of an overdense plasma (where lasers cannot penetrate) by highly energetic collision-less <span class="hlt">electrons</span>. A direct application of this mechanism to Fast Ignition (FT) experiments is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070032045','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070032045"><span id="translatedtitle">High-Performance, Radiation-Hardened <span class="hlt">Electronics</span> for Space <span class="hlt">Environments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Keys, Andrew S.; Watson, Michael D.; Frazier, Donald O.; Adams, James H.; Johnson, Michael A.; Kolawa, Elizabeth A.</p> <p>2007-01-01</p> <p>The Radiation Hardened <span class="hlt">Electronics</span> for Space <span class="hlt">Environments</span> (RHESE) project endeavors to advance the current state-of-the-art in high-performance, radiation-hardened <span class="hlt">electronics</span> and processors, ensuring successful performance of space systems required to operate within extreme radiation and temperature <span class="hlt">environments</span>. Because RHESE is a project within the Exploration Technology Development Program (ETDP), RHESE's primary customers will be the human and robotic missions being developed by NASA's Exploration Systems Mission Directorate (ESMD) in partial fulfillment of the Vision for Space Exploration. Benefits are also anticipated for NASA's science missions to planetary and deep-space destinations. As a technology development effort, RHESE provides a broad-scoped, full spectrum of approaches to environmentally harden space <span class="hlt">electronics</span>, including new materials, advanced design processes, reconfigurable hardware techniques, and software modeling of the radiation <span class="hlt">environment</span>. The RHESE sub-project tasks are: SelfReconfigurable <span class="hlt">Electronics</span> for Extreme <span class="hlt">Environments</span>, Radiation Effects Predictive Modeling, Radiation Hardened Memory, Single Event Effects (SEE) Immune Reconfigurable Field Programmable Gate Array (FPGA) (SIRF), Radiation Hardening by Software, Radiation Hardened High Performance Processors (HPP), Reconfigurable Computing, Low Temperature Tolerant MEMS by Design, and Silicon-Germanium (SiGe) Integrated <span class="hlt">Electronics</span> for Extreme <span class="hlt">Environments</span>. These nine sub-project tasks are managed by technical leads as located across five different NASA field centers, including Ames Research Center, Goddard Space Flight Center, the Jet Propulsion Laboratory, Langley Research Center, and Marshall Space Flight Center. The overall RHESE integrated project management responsibility resides with NASA's Marshall Space Flight Center (MSFC). Initial technology development emphasis within RHESE focuses on the hardening of Field Programmable Gate Arrays (FPGA)s and Field Programmable Analog</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1080174','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1080174"><span id="translatedtitle"><span class="hlt">Electronic</span> and spin <span class="hlt">transport</span> properties of graphene nanoribbon mediated by metal adatoms: a study by the QUAMBO-NEGF approach</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhang, G. P.; Liu, Xiaojie; Wang, C. Z.; Yao, Y. X.; Zhang, Jian; Ho, K. M.</p> <p>2013-02-12</p> <p>Structural and <span class="hlt">electronic</span> properties, including deformation, magnetic moment, Mulliken population, bond order, as well as <span class="hlt">electronic</span> <span class="hlt">transport</span> properties, of zigzag graphene nanoribbon (ZGNR) with Co adatoms on hollow sites are investigated by quasi-atomic minimal basis orbits (QUAMBOs), a first-principles tight binding (TB) scheme based on density functional theory (DFT), combined with a non-equilibrium Green's function. For <span class="hlt">electronic</span> <span class="hlt">transport</span>, below the Fermi level the transmission is strongly suppressed and spin dependent as a result of magnetism by Co adatom adsorption, while above the Fermi level the transmission is slightly distorted and spin independent. Due to the local <span class="hlt">environment</span> dependence of QUAMBOs–TB parameters, we construct QUAMBOs–TB parameters of ZGNR leads and ZGNR with Co adatoms on hollow center sites by a divide-and-conquer approach, and accurately reproduce the <span class="hlt">electronic</span> transmission behavior. Our QUAMBO–NEGF method is a new and promising way of examining <span class="hlt">electronic</span> <span class="hlt">transport</span> in large-scale systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130013147','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130013147"><span id="translatedtitle">High Temperature Wireless Communication And <span class="hlt">Electronics</span> For Harsh <span class="hlt">Environment</span> Applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hunter, G. W.; Neudeck, P. G.; Beheim, G. M.; Ponchak, G. E.; Chen, L.-Y</p> <p>2007-01-01</p> <p>In order for future aerospace propulsion systems to meet the increasing requirements for decreased maintenance, improved capability, and increased safety, the inclusion of intelligence into the propulsion system design and operation becomes necessary. These propulsion systems will have to incorporate technology that will monitor propulsion component conditions, analyze the incoming data, and modify operating parameters to optimize propulsion system operations. This implies the development of sensors, actuators, and <span class="hlt">electronics</span>, with associated packaging, that will be able to operate under the harsh <span class="hlt">environments</span> present in an engine. However, given the harsh <span class="hlt">environments</span> inherent in propulsion systems, the development of engine-compatible <span class="hlt">electronics</span> and sensors is not straightforward. The ability of a sensor system to operate in a given <span class="hlt">environment</span> often depends as much on the technologies supporting the sensor element as the element itself. If the supporting technology cannot handle the application, then no matter how good the sensor is itself, the sensor system will fail. An example is high temperature <span class="hlt">environments</span> where supporting technologies are often not capable of operation in engine conditions. Further, for every sensor going into an engine <span class="hlt">environment</span>, i.e., for every new piece of hardware that improves the in-situ intelligence of the components, communication wires almost always must follow. The communication wires may be within or between parts, or from the engine to the controller. As more hardware is added, more wires, weight, complexity, and potential for unreliability is also introduced. Thus, wireless communication combined with in-situ processing of data would significantly improve the ability to include sensors into high temperature systems and thus lead toward more intelligent engine systems. NASA Glenn Research Center (GRC) is presently leading the development of <span class="hlt">electronics</span>, communication systems, and sensors capable of prolonged stable</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012asim.book..119Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012asim.book..119Q"><span id="translatedtitle">Probing <span class="hlt">Electronic</span> <span class="hlt">Transport</span> of Individual Nanostructures with Atomic Precision</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qin, Shengyong; Li, An-Ping</p> <p></p> <p>Accessing individual nanostructures with atomic precision is an important process in the bottom-up fabrication and characterization of <span class="hlt">electronic</span> nanodevices. Local electrical contacts, namely nanoelectrodes, are often fabricated by using top-down lithography and chemical etching techniques. These processes however lack atomic precision and introduce the possibility of contamination. Here, we review recent reports on the application of a field-induced emission process in the fabrication of local contacts onto individual nanowires and nanotubes with atomic spatial precision. In this method, gold nanoislands are deposited onto nanostructures precisely by using a scanning tunneling microscope tip, which provides a clean and controllable process to ensure both electrically conductive and mechanically reliable contacts. The applicability of the technique has been demonstrated in a wide variety of nanostructures, including silicide atomic wires, carbon nanotubes, and copper nanowires. These local contacts bridge the nanostructures and the <span class="hlt">transport</span> probes, allowing for the measurements of both electrical <span class="hlt">transport</span> and scanning tunneling microscopy on the same nanostructures in situ. The direct correlation between <span class="hlt">electronic</span> and <span class="hlt">transport</span> properties and atomic structures can be explored on individual nanostructures at the unprecedented atomic level.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1040753','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1040753"><span id="translatedtitle">Probing <span class="hlt">electronic</span> <span class="hlt">transport</span> of individual nanostructures with atomic precision</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Qin, Shengyong; Li, An-Ping</p> <p>2012-01-01</p> <p>Accessing individual nanostructures with atomic precision is an important process in the bottom-up fabrication and characterization of <span class="hlt">electronic</span> nanodevices. Local electrical contacts, namely nanoelectrodes, are often fabricated by using top-down lithography and chemical etching techniques. These processes however lack atomic precision and introduce the possibility of contamination. Here, we review recent reports on the application of a field-induced emission process in the fabrication of local contacts onto individual nanowires and nanotubes with atomic spatial precision. In this method, gold nanoislands are deposited onto nanostructures precisely by using a scanning tunneling microscope tip, which provides a clean and controllable process to ensure both electrically conductive and mechanically reliable contacts. The applicability of the technique has been demonstrated in a wide variety of nanostructures, including silicide atomic wires, carbon nanotubes, and copper nanowires. These local contacts bridge the nanostructures and the <span class="hlt">transport</span> probes, allowing for the measurements of both electrical <span class="hlt">transport</span> and scanning tunneling microscopy on the same nanostructures in situ. The direct correlation between <span class="hlt">electronic</span> and <span class="hlt">transport</span> properties and atomic structures can be explored on individual nanostructures at the unprecedented atomic level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/accomplishments/documents/fullText/ACC0141.pdf','DOE-RDACC'); return false;" href="http://www.osti.gov/accomplishments/documents/fullText/ACC0141.pdf"><span id="translatedtitle">Helium, Iron and <span class="hlt">Electron</span> Particle <span class="hlt">Transport</span> and Energy <span class="hlt">Transport</span> Studies on the TFTR Tokamak</span></a></p> <p><a target="_blank" href="http://www.osti.gov/accomplishments/fieldedsearch.html">DOE R&D Accomplishments Database</a></p> <p>Synakowski, E. J.; Efthimion, P. C.; Rewoldt, G.; Stratton, B. C.; Tang, W. M.; Grek, B.; Hill, K. W.; Hulse, R. A.; Johnson, D .W.; Mansfield, D. K.; McCune, D.; Mikkelsen, D. R.; Park, H. K.; Ramsey, A. T.; Redi, M. H.; Scott, S. D.; Taylor, G.; Timberlake, J.; Zarnstorff, M. C. (Princeton Univ., NJ (United States). Plasma Physics Lab.); Kissick, M. W. (Wisconsin Univ., Madison, WI (United States))</p> <p>1993-03-01</p> <p>Results from helium, iron, and <span class="hlt">electron</span> <span class="hlt">transport</span> on TFTR in L-mode and Supershot deuterium plasmas with the same toroidal field, plasma current, and neutral beam heating power are presented. They are compared to results from thermal <span class="hlt">transport</span> analysis based on power balance. Particle diffusivities and thermal conductivities are radially hollow and larger than neoclassical values, except possibly near the magnetic axis. The ion channel dominates over the <span class="hlt">electron</span> channel in both particle and thermal diffusion. A peaked helium profile, supported by inward convection that is stronger than predicted by neoclassical theory, is measured in the Supershot The helium profile shape is consistent with predictions from quasilinear electrostatic drift-wave theory. While the perturbative particle diffusion coefficients of all three species are similar in the Supershot, differences are found in the L-Mode. Quasilinear theory calculations of the ratios of impurity diffusivities are in good accord with measurements. Theory estimates indicate that the ion heat flux should be larger than the <span class="hlt">electron</span> heat flux, consistent with power balance analysis. However, theoretical values of the ratio of the ion to <span class="hlt">electron</span> heat flux can be more than a factor of three larger than experimental values. A correlation between helium diffusion and ion thermal <span class="hlt">transport</span> is observed and has favorable implications for sustained ignition of a tokamak fusion reactor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10141674','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10141674"><span id="translatedtitle">Helium, iron and <span class="hlt">electron</span> particle <span class="hlt">transport</span> and energy <span class="hlt">transport</span> studies on the TFTR tokamak</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Synakowski, E.J.; Efthimion, P.C.; Rewoldt, G.; Stratton, B.C.; Tang, W.M.; Grek, B.; Hill, K.W.; Hulse, R.A.; Johnson, D.W.; Mansfield, D.K.; McCune, D.; Mikkelsen, D.R.; Park, H.K.; Ramsey, A.T.; Redi, M.H.; Scott, S.D.; Taylor, G.; Timberlake, J.; Zarnstorff, M.C.; Kissick, M.W.</p> <p>1993-03-01</p> <p>Results from helium, iron, and <span class="hlt">electron</span> <span class="hlt">transport</span> on TFTR in L-mode and Supershot deuterium plasmas with the same toroidal field, plasma current, and neutral beam heating power are presented. They are compared to results from thermal <span class="hlt">transport</span> analysis based on power balance. Particle diffusivities and thermal conductivities are radially hollow and larger than neoclassical values, except possibly near the magnetic axis. The ion channel dominates over the <span class="hlt">electron</span> channel in both particle and thermal diffusion. A peaked helium profile, supported by inward convection that is stronger than predicted by neoclassical theory, is measured in the Supershot The helium profile shape is consistent with predictions from quasilinear electrostatic drift-wave theory. While the perturbative particle diffusion coefficients of all three species are similar in the Supershot, differences are found in the L-Mode. Quasilinear theory calculations of the ratios of impurity diffusivities are in good accord with measurements. Theory estimates indicate that the ion heat flux should be larger than the <span class="hlt">electron</span> heat flux, consistent with power balance analysis. However, theoretical values of the ratio of the ion to <span class="hlt">electron</span> heat flux can be more than a factor of three larger than experimental values. A correlation between helium diffusion and ion thermal <span class="hlt">transport</span> is observed and has favorable implications for sustained ignition of a tokamak fusion reactor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PhDT........73D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PhDT........73D&link_type=ABSTRACT"><span id="translatedtitle">Understanding <span class="hlt">electronic</span> structure and <span class="hlt">transport</span> properties in nanoscale junctions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dhungana, Kamal B.</p> <p></p> <p>Understanding the <span class="hlt">electronic</span> structure and the <span class="hlt">transport</span> properties of nanoscale materials are pivotal for designing future nano-scale <span class="hlt">electronic</span> devices. Nanoscale materials could be individual or groups of molecules, nanotubes, semiconducting quantum dots, and biomolecules. Among these several alternatives, organic molecules are very promising and the field of molecular <span class="hlt">electronics</span> has progressed significantly over the past few decades. Despite these progresses, it has not yet been possible to achieve atomic level control at the metal-molecule interface during a conductance measurement, which hinders the progress in this field. The lack of atomic level information of the interface also makes it much harder for theorist to interpret the experimental results. To identify the junction configuration that possibly exists during the experimental measurement of conductance in molecular junction, we created an ensemble of Ruthanium-bis(terpyridine) molecular devices, and studied the <span class="hlt">transport</span> behavior in these molecular junctions. This helps us identifying the junction geometry that yields the experimentally measured current-voltage characteristics. Today's <span class="hlt">electronic</span> devices mostly ignore the spin effect of an <span class="hlt">electron</span>. The inclusion of spin effect of an <span class="hlt">electron</span> on solid-state transistor allows us to build more efficient <span class="hlt">electronic</span> devices; this also alleviates the problem of huge heat dissipation in the nanoscale <span class="hlt">electronic</span> devices. Different materials have been utilized to build three terminals spin transistor since its inception in 1950. In search of suitable candidates for the molecular spin transistor, we have recently designed a spin-valve transistor based on an organometallic molecule; a large amplification (320 %) in tunnel magneto-resistance (TMR) is found to occur at an experimentally accessible gate field. This suggests that the organic molecules can be utilized for making the next generation three terminal spintronic devices. Similarly, we have designed a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21439580','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21439580"><span id="translatedtitle">Numerical Investigation of Laser Propulsion for <span class="hlt">Transport</span> in Water <span class="hlt">Environment</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Han Bing; Li Beibei; Zhang Hongchao; Chen Jun; Shen Zhonghua; Lu Jian; Ni Xiaowu</p> <p>2010-10-08</p> <p>Problems that cumber the development of the laser propulsion in atmosphere and vacuum are discussed. Based on the theory of interaction between high-intensity laser and materials, as air and water, it is proved that <span class="hlt">transport</span> in water <span class="hlt">environment</span> can be impulsed by laser. The process of laser propulsion in water is investigated theoretically and numerically. It shows that not only the laser induced plasma shock wave, but also the laser induced bubble oscillation shock waves and the pressure induced by the collapsing bubble can be used. Many experimental results show that the theory and the numerical results are valid. The numerical result of the contribution of every propulsion source is given in percentage. And the maximum momentum coupling coefficient Cm is given. Laser propulsion in water <span class="hlt">environment</span> can be applied in many fields. For example, it can provide highly controllable forces of the order of micro-Newton ({mu}N) in microsystems, such as the MEMS (Micro-electromechanical Systems). It can be used as minimally invasive surgery tools of high temporal and spatial resolution. It can be used as the propulsion source in marine survey and exploitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22412974','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22412974"><span id="translatedtitle"><span class="hlt">Electron</span> and hole <span class="hlt">transport</span> in ambipolar, thin film pentacene transistors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Saudari, Sangameshwar R.; Kagan, Cherie R.</p> <p>2015-01-21</p> <p>Solution-processed, ambipolar, thin-film pentacene field-effect transistors were employed to study both <span class="hlt">electron</span> and hole <span class="hlt">transport</span> simultaneously in a single, organic solid-state device. <span class="hlt">Electron</span> and hole mobilities were extracted from the respective unipolar saturation regimes and show thermally activated behavior and gate voltage dependence. We fit the gate voltage dependent saturation mobility to a power law to extract the characteristic Meyer-Neldel (MN) energy, a measure of the width of the exponential distribution of localized states extending into the energy gap of the organic semiconductor. The MN energy is ∼78 and ∼28 meV for <span class="hlt">electrons</span> and holes, respectively, which reflects a greater density of localized tail states for <span class="hlt">electrons</span> than holes. This is consistent with the lower measured <span class="hlt">electron</span> than hole mobility. For holes, the well-behaved linear regime allows for four-point probe measurement of the contact resistance independent mobility and separate characterization of the width of the localized density of states, yielding a consistent MN energy of 28 meV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4791957','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4791957"><span id="translatedtitle">Nanoscale <span class="hlt">Electron</span> <span class="hlt">Transport</span> Measurements of Immobilized Cytochrome P450 Proteins</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bostick, Christopher D.; Flora, Darcy R.; Gannett, Peter M.; Tracy, Timothy S.; Lederman, David</p> <p>2015-01-01</p> <p>Gold nanopillars, functionalized with an organic self-assembled monolayer, can be used to measure the electrical conductance properties of immobilized proteins without aggregation. Measurements of the conductance of nanopillars with cytochrome P450 2C9 (CYP2C9) proteins using conducting probe atomic force microscopy demonstrate that a correlation exists between the energy barrier height between hopping sites and CYP2C9 metabolic activity. Measurements performed as a function of tip force indicate that, when subjected to a large force, the protein is more stable in the presence of a substrate. This agrees with the hypothesis that substrate entry into the active site helps to stabilize the enzyme. The relative distance between hopping sites also increases with increasing force, possibly because protein functional groups responsible for <span class="hlt">electron</span> <span class="hlt">transport</span> depend on the structure of the protein. The inhibitor sulfaphenazole, in addition to the previously studied aniline, increased the barrier height for <span class="hlt">electron</span> transfer and thereby makes CYP2C9 reduction more difficult and inhibits metabolism. This suggests that P450 Type II binders may decrease the ease of <span class="hlt">electron</span> <span class="hlt">transport</span> processes in the enzyme, in addition to occupying the active site. PMID:25804257</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3552782','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3552782"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> in a GaPSb film</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>We have performed <span class="hlt">transport</span> measurements on a gallium phosphide antimonide (GaPSb) film grown on GaAs. At low temperatures (T), <span class="hlt">transport</span> is governed by three-dimensional Mott variable range hopping (VRH) due to strong localization. Therefore, electron–<span class="hlt">electron</span> interactions are not significant in GaPSb. With increasing T, the coexistence of VRH conduction and the activated behavior with a gap of 20 meV is found. The fact that the measured gap is comparable to the thermal broadening at room temperature (approximately 25 meV) demonstrates that <span class="hlt">electrons</span> can be thermally activated in an intrinsic GaPSb film. Moreover, the observed carrier density dependence on temperature also supports the coexistence of VRH and the activated behavior. It is shown that the carriers are delocalized either with increasing temperature or magnetic field in GaPSb. Our new experimental results provide important information regarding GaPSb which may well lay the foundation for possible GaPSb-based device applications such as in high-<span class="hlt">electron</span>-mobility transistor and heterojunction bipolar transistors. PMID:23173952</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2806741','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2806741"><span id="translatedtitle">Electrokinesis is a microbial behavior that requires extracellular <span class="hlt">electron</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Harris, H. W.; El-Naggar, M. Y.; Bretschger, O.; Ward, M. J.; Romine, M. F.; Obraztsova, A. Y.; Nealson, K. H.</p> <p>2009-01-01</p> <p>We report a previously undescribed bacterial behavior termed electrokinesis. This behavior was initially observed as a dramatic increase in cell swimming speed during reduction of solid MnO2 particles by the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1. The same behavioral response was observed when cells were exposed to small positive applied potentials at the working electrode of a microelectrochemical cell and could be tuned by adjusting the potential on the working electrode. Electrokinesis was found to be different from both chemotaxis and galvanotaxis but was absent in mutants defective in <span class="hlt">electron</span> <span class="hlt">transport</span> to solid metal oxides. Using in situ video microscopy and cell tracking algorithms, we have quantified the response for different strains of Shewanella and shown that the response correlates with current-generating capacity in microbial fuel cells. The electrokinetic response was only exhibited by a subpopulation of cells closest to the MnO2 particles or electrodes. In contrast, the addition of 1 mM 9,10-anthraquinone-2,6-disulfonic acid, a soluble <span class="hlt">electron</span> shuttle, led to increases in motility in the entire population. Electrokinesis is defined as a behavioral response that requires functional extracellular <span class="hlt">electron</span> <span class="hlt">transport</span> and that is observed as an increase in cell swimming speeds and lengthened paths of motion that occur in the proximity of a redox active mineral surface or the working electrode of an electrochemical cell. PMID:20018675</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..MART16001N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..MART16001N"><span id="translatedtitle">Multiscale modelling of charge <span class="hlt">transport</span> in organic <span class="hlt">electronic</span> materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nelson, Jenny</p> <p>2010-03-01</p> <p>Charge <span class="hlt">transport</span> in disordered organic semiconductors is controlled by a complex combination of phenomena that span a range of length and time scales. As a result, it is difficult to rationalize charge <span class="hlt">transport</span> properties in terms of material parameters. Until now, efforts to improve charge mobilities in molecular semiconductors have proceeded largely by trial and error rather than through systematic design. However, recent developments have enabled the first predictive simulation studies of charge <span class="hlt">transport</span> in disordered organic semiconductors. In this presentation we will show how a set of computational methods, namely molecular modelling methods to simulate molecular packing, quantum chemical calculations of charge transfer rates, and Monte Carlo simulations of charge <span class="hlt">transport</span> can be used to reproduce experimental charge mobilities with few or no fitting parameters. Using case studies, we will show how such simulations can explain the relative values of <span class="hlt">electron</span> and hole mobility and the effects of grain size, side chains and polymer molecular weight on charge mobility. Although currently applied to material systems of relatively high symmetry or well defined structure, this approach can be developed to address more complex systems such as multicomponent solids and conjugated polymers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1036575','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1036575"><span id="translatedtitle">Contacting nanowires and nanotubes with atomic precision for <span class="hlt">electronic</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Qin, Shengyong; Hellstrom, Sondra L; Bao, Zhenan; Boyanov, Boyan; Li, An-Ping</p> <p>2012-01-01</p> <p>Making contacts to nanostructures with atomic precision is an important process in the bottom-up fabrication and characterization of <span class="hlt">electronic</span> nanodevices. Existing contacting techniques use top-down lithography and chemical etching, but lack atomic precision and introduce the possibility of contamination. Here, we report that a field-induced emission process can be used to make local contacts onto individual nanowires and nanotubes with atomic spatial precision. The gold nano-islands are deposited onto nanostructures precisely by using a scanning tunneling microscope tip, which provides a clean and controllable method to ensure both electrically conductive and mechanically reliable contacts. To demonstrate the wide applicability of the technique, nano-contacts are fabricated on silicide atomic wires, carbon nanotubes, and copper nanowires. The electrical <span class="hlt">transport</span> measurements are performed in situ by utilizing the nanocontacts to bridge the nanostructures to the <span class="hlt">transport</span> probes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002JMMM..240..117F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002JMMM..240..117F"><span id="translatedtitle"><span class="hlt">Transport</span> properties and <span class="hlt">electronic</span> structure of epitaxial tunnel junctions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Freyss, M.; Papanikolaou, N.; Bellini, V.; Zeller, R.; Dederichs, P. H.; Turek, I.</p> <p>2002-02-01</p> <p>We present ab initio calculations for the <span class="hlt">electronic</span> ground-state and <span class="hlt">transport</span> properties of epitaxial Fe/semiconductor/Fe (0 0 1) tunnel junctions. The ground state properties are determined by the ab initio Screened KKR Green's function method and the <span class="hlt">transport</span> properties by a Green's function formulation of the Landauer-Büttiker formalism. We focus on tunnel junctions with a semiconducting ZnSe barrier and compare them to results for junctions with Si and GaAs barriers. We comment on the presence of metal-induced gap states (MIGS) in the semiconductor, the spin polarization of which strongly depends on the nature of the barrier. We investigate furthermore the influence of one atomic layer at the interface of a non-magnetic metal (Cu, Ag, Al) and of a magnetic 3d transition metal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5197113','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5197113"><span id="translatedtitle">Conservative differencing of the <span class="hlt">electron</span> Fokker-Planck <span class="hlt">transport</span> equation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Langdon, A.B.</p> <p>1981-01-12</p> <p>We need to extend the applicability and improve the accuracy of kinetic <span class="hlt">electron</span> <span class="hlt">transport</span> codes. In this paper, special attention is given to modelling of e-e collisions, including the dominant contributions arising from anisotropy. The electric field and spatial gradient terms are also considered. I construct finite-difference analogues to the Fokker-Planck integral-differential collision operator, which conserve the particle number, momentum and energy integrals (sums) regardless of the coarseness of the velocity zoning. Such properties are usually desirable, but are especially useful, for example, when there are spatial regions and/or time intervals in which the plasma is cool, so that the collision operator acts rapidly and the velocity distribution is poorly resolved, yet it is crucial that gross conservation properties be respected in hydro-<span class="hlt">transport</span> applications, such as in the LASNEX code. Some points are raised concerning spatial differencing and time integration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT.........6B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT.........6B"><span id="translatedtitle">Nanoscale <span class="hlt">transport</span> of <span class="hlt">electrons</span> and ions in water</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boynton, Paul Christopher</p> <p></p> <p>The following dissertation discusses the theoretical study of water on the nanoscale, often involved with essential biological molecules such as DNA and proteins. First I introduce the study of water on the nanoscale and how experimentalists approach confinement with nanopores and nanogaps. Then I discuss the theoretical method we choose for understanding this important biological medium on the molecular level, namely classical molecular dynamics. This leads into <span class="hlt">transport</span> mechanisms that utilize water on the nanoscale, in our case <span class="hlt">electronic</span> and ionic <span class="hlt">transport</span>. On the scale of mere nanometers or less <span class="hlt">electronic</span> <span class="hlt">transport</span> in water enters the tunneling regime, requiring the use of a quantum treatment. In addition, I discuss the importance of water in ionic <span class="hlt">transport</span> and its known effects on biological phenomena such as ion selectivity. Water also has great influence over DNA and proteins, which are both introduced in the context of nanopore sequencing. Several techniques for nanopore sequencing are examined and the importance of protein sequencing is explained. In Chapter 2, we study the effect of volumetric constraints on the structure and <span class="hlt">electronic</span> <span class="hlt">transport</span> properties of distilled water in a nanopore with embedded electrodes. Combining classical molecular dynamics simulations with quantum scattering theory, we show that the structural motifs water assumes inside the pore can be probed directly by tunneling. In Chapter 3, we propose an improvement to the original sequencing by tunneling method, in which N pairs of electrodes are built in series along a synthetic nanochannel. Each current time series for each nucleobase is cross-correlated together, reducing noise in the signals. We show using random sampling of data from classical molecular dynamics, that indeed the sequencing error is significantly reduced as the number of pairs of electrodes, N, increases. In Chapter 4, we propose a new technique for de novo protein sequencing that involves translocating a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3986668','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3986668"><span id="translatedtitle">Inverted organic photovoltaic device with a new <span class="hlt">electron</span> <span class="hlt">transport</span> layer</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>We demonstrate that there is a new solution-processed <span class="hlt">electron</span> <span class="hlt">transport</span> layer, lithium-doped zinc oxide (LZO), with high-performance inverted organic photovoltaic device. The device exhibits a fill factor of 68.58%, an open circuit voltage of 0.86 V, a short-circuit current density of −9.35 cm/mA2 along with 5.49% power conversion efficiency. In addition, we studied the performance of blend ratio dependence on inverted organic photovoltaics. Our device also demonstrates a long stability shelf life over 4 weeks in air. PMID:24674457</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016APS..MARX23001T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016APS..MARX23001T&link_type=ABSTRACT"><span id="translatedtitle">Thermal and <span class="hlt">Electronic</span> <span class="hlt">Transport</span> in Inorganic and Organic Thermoelectric Materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, Zhiting</p> <p></p> <p>In this talk, we will first talk about first-principles calculations of phonon and <span class="hlt">electron</span> <span class="hlt">transport</span> in inorganic thermoelectric materials. We will start with rocksalt PbTe and PbSe, and move on to wurtzite ZnO. We will emphasize the strategies to reduce the lattice thermal conductivity. Then we apply first-principles calculations to organic thermoelectric materials. The thermoelectric properties of doped polypyrrole (PPy) will be discussed. In addition, we will cover the chain confinement effects observed in amorphous polymer thin films using molecular dynamics simulations, which highlights the fundamental difference in heat conduction between crystalline polymers and amorphous polymers</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3896775','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3896775"><span id="translatedtitle">Orthogonally modulated molecular <span class="hlt">transport</span> junctions for resettable <span class="hlt">electronic</span> logic gates</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Meng, Fanben; Hervault, Yves-Marie; Shao, Qi; Hu, Benhui; Norel, Lucie; Rigaut, Stéphane; Chen, Xiaodong</p> <p>2014-01-01</p> <p>Individual molecules have been demonstrated to exhibit promising applications as functional components in the fabrication of computing nanocircuits. Based on their advantage in chemical tailorability, many molecular devices with advanced <span class="hlt">electronic</span> functions have been developed, which can be further modulated by the introduction of external stimuli. Here, orthogonally modulated molecular <span class="hlt">transport</span> junctions are achieved via chemically fabricated nanogaps functionalized with dithienylethene units bearing organometallic ruthenium fragments. The addressable and stepwise control of molecular isomerization can be repeatedly and reversibly completed with a judicious use of the orthogonal optical and electrochemical stimuli to reach the controllable switching of conductivity between two distinct states. These photo-/electro-cooperative nanodevices can be applied as resettable <span class="hlt">electronic</span> logic gates for Boolean computing, such as a two-input OR and a three-input AND-OR. The proof-of-concept of such logic gates demonstrates the possibility to develop multifunctional molecular devices by rational chemical design. PMID:24394717</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyE...76...12F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyE...76...12F"><span id="translatedtitle">Time dependent <span class="hlt">electronic</span> <span class="hlt">transport</span> in chiral edge channels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fève, G.; Berroir, J.-M.; Plaçais, B.</p> <p>2016-02-01</p> <p>We study time dependent <span class="hlt">electronic</span> <span class="hlt">transport</span> along the chiral edge channels of the quantum Hall regime, focusing on the role of Coulomb interaction. In the low frequency regime, the a.c. conductance can be derived from a lumped element description of the circuit. At higher frequencies, the propagation equations of the Coulomb coupled edge channels need to be solved. As a consequence of the interchannel coupling, a charge pulse emitted in a given channel fractionalized in several pulses. In particular, Coulomb interaction between channels leads to the fractionalization of a charge pulse emitted in a given channel in several pulses. We finally study how the Coulomb interaction, and in particular the fractionalization process, affects the propagation of a single <span class="hlt">electron</span> in the circuit. All the above-mentioned topics are illustrated by experimental realizations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyE...82..129F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyE...82..129F"><span id="translatedtitle">Reprint of : Time dependent <span class="hlt">electronic</span> <span class="hlt">transport</span> in chiral edge channels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fève, G.; Berroir, J.-M.; Plaçais, B.</p> <p>2016-08-01</p> <p>We study time dependent <span class="hlt">electronic</span> <span class="hlt">transport</span> along the chiral edge channels of the quantum Hall regime, focusing on the role of Coulomb interaction. In the low frequency regime, the a.c. conductance can be derived from a lumped element description of the circuit. At higher frequencies, the propagation equations of the Coulomb coupled edge channels need to be solved. As a consequence of the interchannel coupling, a charge pulse emitted in a given channel fractionalized in several pulses. In particular, Coulomb interaction between channels leads to the fractionalization of a charge pulse emitted in a given channel in several pulses. We finally study how the Coulomb interaction, and in particular the fractionalization process, affects the propagation of a single <span class="hlt">electron</span> in the circuit. All the above-mentioned topics are illustrated by experimental realizations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SeScT..31f5012Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SeScT..31f5012Y"><span id="translatedtitle">Analytical band Monte Carlo analysis of <span class="hlt">electron</span> <span class="hlt">transport</span> in silicene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yeoh, K. H.; Ong, D. S.; Ooi, C. H. Raymond; Yong, T. K.; Lim, S. K.</p> <p>2016-06-01</p> <p>An analytical band Monte Carlo (AMC) with linear energy band dispersion has been developed to study the <span class="hlt">electron</span> <span class="hlt">transport</span> in suspended silicene and silicene on aluminium oxide (Al2O3) substrate. We have calibrated our model against the full band Monte Carlo (FMC) results by matching the velocity-field curve. Using this model, we discover that the collective effects of charge impurity scattering and surface optical phonon scattering can degrade the <span class="hlt">electron</span> mobility down to about 400 cm2 V-1 s-1 and thereafter it is less sensitive to the changes of charge impurity in the substrate and surface optical phonon. We also found that further reduction of mobility to ˜100 cm2 V-1 s-1 as experimentally demonstrated by Tao et al (2015 Nat. Nanotechnol. 10 227) can only be explained by the renormalization of Fermi velocity due to interaction with Al2O3 substrate.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006JPhy4.133..405K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006JPhy4.133..405K&link_type=ABSTRACT"><span id="translatedtitle">Behaviour of fast <span class="hlt">electron</span> <span class="hlt">transport</span> in solid targets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koenig, M.; Baton, S. D.; Benuzzi-Mounaix, A.; Fuchs, J.; Loupias, B.; Guillou, P.; Batani, D.; Morace, A.; Piazza, D.; Kodama, R.; Norimatsu, T.; Nakatsutsumi, M.; Aglitskiy, Y.; Rousseaux, C.</p> <p>2006-06-01</p> <p>One of the main issues of the fast ignitor scheme is the role of fast <span class="hlt">electron</span> <span class="hlt">transport</span> in the solid fuel heating. Recent experiments used a new target scheme based on the use of cone to guide the PW laser and enhance the <span class="hlt">electron</span> production. In this context it is fundamental to understand the physics underlying this new target scheme. We report here recent and preliminary results of ultra-intense laser pulse interaction with three layer targets in presence of the cone or without. Experiments have been performed at LULI with the 100 TW laser facility, at intensities up to 3 1019 W/cm2. Several diagnostics have been implemented (2D Kα imaging, Kα spectroscopy and rear side imaging, protons emission) to quantify the cone effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25307017','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25307017"><span id="translatedtitle">Semiconducting black phosphorus: synthesis, <span class="hlt">transport</span> properties and <span class="hlt">electronic</span> applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Han; Du, Yuchen; Deng, Yexin; Ye, Peide D</p> <p>2015-05-01</p> <p>Phosphorus is one of the most abundant elements preserved in earth, and it comprises a fraction of ∼0.1% of the earth crust. In general, phosphorus has several allotropes, and the two most commonly seen allotropes, i.e. white and red phosphorus, are widely used in explosives and safety matches. In addition, black phosphorus, though rarely mentioned, is a layered semiconductor and has great potential in optical and <span class="hlt">electronic</span> applications. Remarkably, this layered material can be reduced to one single atomic layer in the vertical direction owing to the van der Waals structure, and is known as phosphorene, in which the physical properties can be tremendously different from its bulk counterpart. In this review article, we trace back to the research history on black phosphorus of over 100 years from the synthesis to material properties, and extend the topic from black phosphorus to phosphorene. The physical and <span class="hlt">transport</span> properties are highlighted for further applications in <span class="hlt">electronic</span> and optoelectronics devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.717a2043O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.717a2043O"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> estimated from <span class="hlt">electron</span> spectra using <span class="hlt">electron</span> spectrometer in LFEX laser target experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ozaki, T.; Hata, M.; Matsuo, K.; Kojima, S.; Arikawa, Y.; Fujioka, S.; Sakagami, H.; Sunahara, A.; Nagatomo, H.; Johzaki, T.; Yogo, A.; Morace, A.; Zhang, Z.; Shiraga, H.; Sakata, S.; Nagai, T.; Abe, Y.; Lee, S.; Nakai, M.; Nishimura, H.; Azechi, H.; FIREX Group; GXII-LFEX Group</p> <p>2016-05-01</p> <p>Hot <span class="hlt">electrons</span> which are generated from targets irradiated by a high-intense laser are measured by two <span class="hlt">electron</span> spectrometers (ESMs). However, total <span class="hlt">electron</span> energy observed by the ESM is only less than 1%. Hot <span class="hlt">electrons</span> are confined by self-fields due to the huge current. When an external magnetic field of several hundred Tesla is applied during the laser irradiation on targets, the ESM signals always increase. In the simulation, the same result can be obtained. The reason is that the Alfvén limit can be mitigated due to the external longitudinal magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6201E..0SO','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6201E..0SO"><span id="translatedtitle">Biochemical <span class="hlt">transport</span> modeling, estimation, and detection in realistic <span class="hlt">environments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ortner, Mathias; Nehorai, Arye</p> <p>2006-05-01</p> <p>Early detection and estimation of the spread of a biochemical contaminant are major issues for homeland security applications. We present an integrated approach combining the measurements given by an array of biochemical sensors with a physical model of the dispersion and statistical analysis to solve these problems and provide system performance measures. We approximate the dispersion model of the contaminant in a realistic <span class="hlt">environment</span> through numerical simulations of reflected stochastic diffusions describing the microscopic <span class="hlt">transport</span> phenomena due to wind and chemical diffusion using the Feynman-Kac formula. We consider arbitrary complex geometries and account for wind turbulence. Localizing the dispersive sources is useful for decontamination purposes and estimation of the cloud evolution. To solve the associated inverse problem, we propose a Bayesian framework based on a random field that is particularly powerful for localizing multiple sources with small amounts of measurements. We also develop a sequential detector using the numerical <span class="hlt">transport</span> model we propose. Sequential detection allows on-line analysis and detecting wether a change has occurred. We first focus on the formulation of a suitable sequential detector that overcomes the presence of unknown parameters (e.g. release time, intensity and location). We compute a bound on the expected delay before false detection in order to decide the threshold of the test. For a fixed false-alarm rate, we obtain the detection probability of a substance release as a function of its location and initial concentration. Numerical examples are presented for two real-world scenarios: an urban area and an indoor ventilation duct.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993PhDT........97G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993PhDT........97G"><span id="translatedtitle">Long-Range Superexchange in <span class="hlt">Electron</span> <span class="hlt">Transport</span> Proteins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gruschus, James Michael</p> <p></p> <p> cytochrome c, as well as plastocyanin, cytochrome b _5, and cytochrome c peroxidase. The surfaces reveal important clues as to which conformations of the <span class="hlt">electron</span> <span class="hlt">transport</span> protein complexes actually give rise to <span class="hlt">electron</span> transfer, a subject of broad biological interest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6202181','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6202181"><span id="translatedtitle"><span class="hlt">Electron</span> heat <span class="hlt">transport</span> in a steep temperature gradient</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rogers, J.H.; De Groot, J.S.; Abou-Assaleh, Z.; Matte, J.P.; Johnston, T.W.; Rosen, M.D.</p> <p>1989-04-01</p> <p>Temporal and spatial measurements of <span class="hlt">electron</span> heat <span class="hlt">transport</span> are made in the University of California Davis AURORA device (J. H. Rogers, Ph.D. dissertation, University of California, Davis, 1987). In AURORA, a microwave pulse heats a region of underdense, collisional, plasma (n/n/sub cr/ approx. <1, where n/sub cr/ = 1.8 x 10/sup 10/ cm/sup -3/ is the critical density, T/sub e//sub 0/ approx. =0.15 eV, and the <span class="hlt">electron</span> scattering mean free path lambda/sub perpendicular/approx. >2 cm). In this region, strong thermal heating (T/sub c/ approx. <0.7 eV) as well as suprathermal heating (T/sub h/approx. =3 eV) is observed. The strong heating results in a steep temperature gradient that violates the approximations of classical heat diffusion theory (L/sub T//lambda/sub perpendicular/approx. >3 for thermal <span class="hlt">electrons</span>, where L/sub T/ = T/sub c/(partialT/sub c//partialz)/sup -1/ is the cold <span class="hlt">electron</span> temperature scale length. The time evolution of the <span class="hlt">electron</span> temperature profile is measured using Langmuir probes. The measured relaxation of the temperature gradient after the microwave pulse is compared to calculations using the Fokker--Planck International code (Phys. Rev. Lett. 49, 1936 (1982)) and the multigroup, flux-limited, target design code LASNEX (Comm. Plasma Phys. 2, 51 (1975)). The <span class="hlt">electron</span> distribution function at the end of the microwave pulse is used as initial conditions for both codes. The Fokker--Planck calculations are found to agree very well with the measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/763897','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/763897"><span id="translatedtitle">Interfacial Charge <span class="hlt">Transport</span> in Organic <span class="hlt">Electronic</span> Materials: the Key to a New <span class="hlt">Electronics</span> Technology</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Smith, D.L.; Campbell, I.H.; Davids, P.S.; Heller, C.M.; Laurich, B.K.; Crone, B.K.; Saxena, A.; Bishop, A.R.; Ferraris, J.P.; Yu, Z.G.</p> <p>1999-06-04</p> <p>This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The primary aim of this project is to obtain a basic scientific understanding of electrical <span class="hlt">transport</span> processes at interfaces that contain an organic <span class="hlt">electronic</span> material. Because of their processing advantages and the tunability of their <span class="hlt">electronic</span> properties, organic <span class="hlt">electronic</span> materials are revolutionizing major technological areas such as information display. We completed an investigation of the fundamental <span class="hlt">electronic</span> excitation energies in the prototype conjugated polymer MEH-PPV. We completed a combined theoretical/experimental study of the energy relation between charged excitations in a conjugated polymer and the metal at a polymer/metal interface. We developed a theoretical model that explains injection currents at polymer/metal interfaces. We have made electrical measurements on devices fabricated using the conjugated polymer MEH-PPV a nd a series of metals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015809','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015809"><span id="translatedtitle">Modeling Ionosphere <span class="hlt">Environments</span>: Creating an ISS <span class="hlt">Electron</span> Density Tool</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gurgew, Danielle N.; Minow, Joseph I.</p> <p>2011-01-01</p> <p>The International Space Station (ISS) maintains an altitude typically between 300 km and 400 km in low Earth orbit (LEO) which itself is situated in the Earth's ionosphere. The ionosphere is a region of partially ionized gas (plasma) formed by the photoionization of neutral atoms and molecules in the upper atmosphere of Earth. It is important to understand what <span class="hlt">electron</span> density the spacecraft is/will be operating in because the ionized gas along the ISS orbit interacts with the electrical power system resulting in charging of the vehicle. One instrument that is already operational onboard the ISS with a goal of monitoring <span class="hlt">electron</span> density, <span class="hlt">electron</span> temperature, and ISS floating potential is the Floating Potential Measurement Unit (FPMU). Although this tool is a valuable addition to the ISS, there are limitations concerning the data collection periods. The FPMU uses the Ku band communication frequency to transmit data from orbit. Use of this band for FPMU data runs is often terminated due to necessary observation of higher priority Extravehicular Activities (EVAs) and other operations on ISS. Thus, large gaps are present in FPMU data. The purpose of this study is to solve the issue of missing environmental data by implementing a secondary <span class="hlt">electron</span> density data source, derived from the COSMIC satellite constellation, to create a model of ISS orbital <span class="hlt">environments</span>. Extrapolating data specific to ISS orbital altitudes, we model the ionospheric <span class="hlt">electron</span> density along the ISS orbit track to supply a set of data when the FPMU is unavailable. This computer model also provides an additional new source of <span class="hlt">electron</span> density data that is used to confirm FPMU is operating correctly and supplements the original environmental data taken by FPMU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhRvB..86o5406K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhRvB..86o5406K"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> through single endohedral Ce@C82 metallofullerenes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaneko, Satoshi; Wang, Lu; Luo, Guangfu; Lu, Jing; Nagase, Shigeru; Sato, Satoru; Yamada, Michio; Slanina, Zdenek; Akasaka, Takeshi; Kiguchi, Manabu</p> <p>2012-10-01</p> <p>The <span class="hlt">electron</span> <span class="hlt">transport</span> through a single endohedral Ce@C82 metallofullerene bridging between metal electrodes was investigated with experimental (break junction) as well as theoretical (density functional theory coupled with the nonequilibrium Green's function formalism) techniques. The single Ce@C82 molecule junction showing a high and fixed conductance value was fabricated by direct binding of the metallofullerene to Ag electrodes. The junction had a conductance of 0.28(±0.05)G0 (G0 = 2e2/h), which was much larger than that of single molecule junctions having anchoring groups (<0.01G0), but only half that of the single C60 molecule junction of 0.5G0. The unexpected reduced conductance of the single Ce@C82 molecule junction compared with that of the single C60 molecule junction was supported by the ab initio quantum <span class="hlt">transport</span> calculations and was explained in terms of the localization of <span class="hlt">electrons</span> in the C82 cage. In the case of the Au electrodes, the single Ce@C82 molecule junction was not formed by the break junction technique because the Ce@C82 molecule could not be trapped in the large Au nanogap, which was formed just after breaking the Au contacts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/477761','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/477761"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> in coupled double quantum wells and wires</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Harff, N.E.; Simmons, J.A.; Lyo, S.K.</p> <p>1997-04-01</p> <p>Due to inter-quantum well tunneling, coupled double quantum wells (DQWs) contain an extra degree of <span class="hlt">electronic</span> freedom in the growth direction, giving rise to new <span class="hlt">transport</span> phenomena not found in single <span class="hlt">electron</span> layers. This report describes work done on coupled DQWs subject to inplane magnetic fields B{sub {parallel}}, and is based on the lead author`s doctoral thesis, successfully defended at Oregon State University on March 4, 1997. First, the conductance of closely coupled DQWs in B{sub {parallel}} is studied. B{sub {parallel}}-induced distortions in the dispersion, the density of states, and the Fermi surface are described both theoretically and experimentally, with particular attention paid to the dispersion anticrossing and resulting partial energy gap. Measurements of giant distortions in the effective mass are found to agree with theoretical calculations. Second, the Landau level spectra of coupled DQWs in tilted magnetic fields is studied. The magnetoresistance oscillations show complex beating as Landau levels from the two Fermi surface components cross the Fermi level. A third set of oscillations resulting from magnetic breakdown is observed. A semiclassical calculation of the Landau level spectra is then performed, and shown to agree exceptionally well with the data. Finally, quantum wires and quantum point contacts formed in DQW structures are investigated. Anticrossings of the one-dimensional DQW dispersion curves are predicted to have interesting <span class="hlt">transport</span> effects in these devices. Difficulties in sample fabrication have to date prevented experimental verification. However, recently developed techniques to overcome these difficulties are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/787905','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/787905"><span id="translatedtitle">Simulations of <span class="hlt">Electron</span> <span class="hlt">Transport</span> in Laser Hot Spots</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>S. Brunner; E. Valeo</p> <p>2001-08-30</p> <p>Simulations of <span class="hlt">electron</span> <span class="hlt">transport</span> are carried out by solving the Fokker-Planck equation in the diffusive approximation. The system of a single laser hot spot, with open boundary conditions, is systematically studied by performing a scan over a wide range of the two relevant parameters: (1) Ratio of the stopping length over the width of the hot spot. (2) Relative importance of the heating through inverse Bremsstrahlung compared to the thermalization through self-collisions. As for uniform illumination [J.P. Matte et al., Plasma Phys. Controlled Fusion 30 (1988) 1665], the bulk of the velocity distribution functions (VDFs) present a super-Gaussian dependence. However, as a result of spatial <span class="hlt">transport</span>, the tails are observed to be well represented by a Maxwellian. A similar dependence of the distributions is also found for multiple hot spot systems. For its relevance with respect to stimulated Raman scattering, the linear Landau damping of the <span class="hlt">electron</span> plasma wave is estimated for such VD Fs. Finally, the nonlinear Fokker-Planck simulations of the single laser hot spot system are also compared to the results obtained with the linear non-local hydrodynamic approach [A.V. Brantov et al., Phys. Plasmas 5 (1998) 2742], thus providing a quantitative limit to the latter method: The hydrodynamic approach presents more than 10% inaccuracy in the presence of temperature variations of the order delta T/T greater than or equal to 1%, and similar levels of deformation of the Gaussian shape of the Maxwellian background.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPCM...24p4209Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPCM...24p4209Z"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> properties of single molecular junctions under mechanical modulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Jianfeng; Guo, Cunlan; Xu, Bingqian</p> <p>2012-04-01</p> <p><span class="hlt">Electron</span> <span class="hlt">transport</span> behaviors of single molecular junctions are very sensitive to the atomic scale molecule-metal electrode contact interfaces, which have been difficult to control. We used a modified scanning probe microscope-break junction technique (SPM-BJT) to control the dynamics of the contacts and simultaneously monitor both the conductance and force. First, by fitting the measured data into a modified multiple tunneling barrier model, the static contact resistances, corresponding to the different contact conformations of single alkanedithiol and alkanediamine molecular junctions, were identified. Second, the changes of contact decay constant were measured under mechanical extensions of the molecular junctions, which helped to classify the different single molecular conductance sets into specific microscopic conformations of the molecule-electrode contacts. Third, by monitoring the changes of force and contact decay constant with the mechanical extensions, the changes of conductance were found to be caused by the changes of contact bond length and by the atomic reorganizations near the contact bond. This study provides a new insight into the understanding of the influences of contact conformations, especially the effect of changes of dynamic contact conformation on <span class="hlt">electron</span> <span class="hlt">transport</span> through single molecular junctions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1047362','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1047362"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">Transport</span> Materials: Synthesis, Properties and Device Performance</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cosimbescu, Lelia; Wang, Liang; Helm, Monte L.; Polikarpov, Evgueni; Swensen, James S.; Padmaperuma, Asanga B.</p> <p>2012-06-01</p> <p>We report the design, synthesis and characterization, thermal and photophysical properties of two silane based <span class="hlt">electron</span> <span class="hlt">transport</span> materials, dibenzo[b,d]thiophen-2-yltriphenylsilane (Si{phi}87) and (dibenzo[b,d]thiophen-2-yl)diphenylsilane (Si{phi}88) and their performance in blue organic light emitting devices (OLEDs). The utility of these materials in blue OLEDs with iridium (III) bis[(4,6-difluorophenyl)-pyridinato-N,C']picolinate (Firpic) as the phosphorescent emitter was demonstrated. Using the silane Si{phi}87 as the <span class="hlt">electron</span> <span class="hlt">transport</span> material (ETm) an EQE of 18.2% was obtained, with a power efficiency of 24.3 lm/W (5.8V at 1mA/cm{sup 2}), in a heterostructure. When Si{phi}88 is used, the EQE is 18.5% with a power efficiency of 26.0 lm/W (5.5V at 1mA/cm{sup 2}).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/266736','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/266736"><span id="translatedtitle">Space applications of the MITS <span class="hlt">electron</span>-photon Monte Carlo <span class="hlt">transport</span> code system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kensek, R.P.; Lorence, L.J.; Halbleib, J.A.; Morel, J.E.</p> <p>1996-07-01</p> <p>The MITS multigroup/continuous-energy <span class="hlt">electron</span>-photon Monte Carlo <span class="hlt">transport</span> code system has matured to the point that it is capable of addressing more realistic three-dimensional adjoint applications. It is first employed to efficiently predict point doses as a function of source energy for simple three-dimensional experimental geometries exposed to simulated uniform isotropic planar sources of monoenergetic <span class="hlt">electrons</span> up to 4.0 MeV. Results are in very good agreement with experimental data. It is then used to efficiently simulate dose to a detector in a subsystem of a GPS satellite due to its natural <span class="hlt">electron</span> <span class="hlt">environment</span>, employing a relatively complex model of the satellite. The capability for survivability analysis of space systems is demonstrated, and results are obtained with and without variance reduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DMP.Q1094S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DMP.Q1094S"><span id="translatedtitle">Computing Rydberg <span class="hlt">Electron</span> <span class="hlt">Transport</span> Rates via Classical Periodic Orbits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sattari, Sulimon; Mitchell, Kevin</p> <p>2016-05-01</p> <p><span class="hlt">Electron</span> <span class="hlt">transport</span> properties of chaotic atomic systems may be computable from classical periodic orbits. This technique allows for replacing a Monte Carlo simulation launching millions of orbits with a sum over tens or hundreds of properly chosen periodic orbits. A firm grasp of the structure of the periodic orbits is required to obtain accurate <span class="hlt">transport</span> rates. We apply a technique called homotopic lobe dynamics (HLD) to understand the structure of periodic orbits to compute the ionization rate of a hydrogen atom in strong parallel electric and magnetic fields. HLD uses information encoded in the intersections of stable and unstable manifolds of a few orbits to compute all relevant periodic orbits in the system. The ionization rate computed from periodic orbits using HLD converges exponentially to the true value as a function of the highest period used. We then use periodic orbit continuation to accurately compute the ionization rate when the field strengths are varied. The ability to use periodic orbits in a mixed phase space could allow for studying <span class="hlt">transport</span> in even more complex few body systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15002024','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15002024"><span id="translatedtitle">Developing Intelligent <span class="hlt">Transportation</span> Systems in an Integrated Systems Analysis <span class="hlt">Environment</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aceves, S M; Paddack, E</p> <p>2002-01-15</p> <p>We are working on developing an Integrated Systems Analysis <span class="hlt">Environment</span> (ISAE) for application to analysis and optimization of Intelligent <span class="hlt">Transportation</span> Systems (ITS). ISAE is based on the concept of Co-simulation, which allows the modeling of complex systems with extreme flexibility. Co-simulation allows the development of virtual ITS systems that can be analyzed and optimized as an overall integrated system. The virtual ITS system is defined by selecting different components from a component library. System component models can be written in multiple programming languages running on different computer platforms. At the same time, ISAE provides full protection for proprietary models. Co-simulation is a cost-effective alternative to competing methodologies, such as developing a translator or selecting a single programming language for all system components. Co-simulation has been recently demonstrated using an example of an automotive system. The demonstration was successfully performed. The paper describes plans on how to implement ISAE and Co-simulation to ITS, and the great advantages that this implementation would represent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21120514','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21120514"><span id="translatedtitle"><span class="hlt">Electron</span> thermal <span class="hlt">transport</span> analysis in Tokamak a Configuration Variable</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Asp, E.; Porte, L.; Alberti, S.; Karpushov, A.; Martin, Y.; Sauter, O.; Turri, G.; Kim, J.-H.; Horton, W.</p> <p>2008-08-15</p> <p>A Tokamak a Configuration Variable (TCV) [G. Tonetti, A. Heym, F. Hofmann et al., in Proceedings of the 16th Symposium on Fusion Technology, London, U.K., edited by R. Hemsworth (North-Holland, Amsterdam, 1991), p. 587] plasma with high power density (up to 8 MW/m{sup 3}) core deposited <span class="hlt">electron</span> cyclotron resonance heating at significant plasma densities ({<=}7x10{sup 19} m{sup -3}) is analyzed for the <span class="hlt">electron</span> thermal <span class="hlt">transport</span>. The discharge distinguishes itself as it has four distinct high confinement mode (H-mode) phases. An Ohmic H-mode with type III edge localized modes (ELMs), which turns into a type I ELMy H-mode when the ECRH is switched on. The ELMs then vanish, which gives rise to a quasistationary ELM-free H-mode. This ELM-free phase can be divided into two, one without magnetohydrodynamics (MHD) and one with. The MHD mode in the latter case causes the confinement to drop by {approx}15%. For all four phases both large-scale trapped <span class="hlt">electron</span> (TEM) and ion temperature gradient (ITG) modes and small-scale <span class="hlt">electron</span> temperature gradient (ETG) modes are analyzed. The analytical TEM formulas have difficulty in explaining both the magnitude and the radial profile of the <span class="hlt">electron</span> thermal flux. Collisionality governs the drive of the TEM, which for the discharge in question implies it can be driven by either the temperature or density gradient. The TEM response function is derived and it is shown to be relatively small and to have sharp resonances in its energy dependence. The ETG turbulence, predicted by the Institute for Fusion Studies <span class="hlt">electron</span> gyrofluid code, is on the other hand driven solely by the <span class="hlt">electron</span> temperature gradient. Both trapped and passing <span class="hlt">electrons</span> add to the ETG instability and turbulent thermal flux. For easy comparison of the results of the above approaches and also with the Weiland model, a dimensionless error measure, the so-called average relative variance is introduced. According to this method the ETG model explains 70% of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007PhDT.......202W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007PhDT.......202W&link_type=ABSTRACT"><span id="translatedtitle">Spin-dependent <span class="hlt">electron</span> <span class="hlt">transport</span> in nanoscale samples</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, Yaguang</p> <p></p> <p>In this thesis, we describe the research in which we use metallic nanoparticles to explore spin-dependent <span class="hlt">electron</span> <span class="hlt">transport</span> at nanometer scale. Nanoscale samples were fabricated by using a state of the art <span class="hlt">electron</span> beam lithography and shadow evaporation technique. We have investigated spin relaxation and decoherence in metallic grains as a function of bias voltage and magnetic field at low temperatures (down to ˜30mK). At low temperatures, the discrete energy levels within a metallic nanoparticle provides a new means to study the physics of the spin-polarized <span class="hlt">electron</span> tunneling. We describe measurements of spin-polarized tunneling via discrete energy levels of single Aluminum grain. Spin polarized current saturates quickly as a function of bias voltage, which demonstrates that the ground state and the lowest excited states carry spin polarized current. The ratio of <span class="hlt">electron</span>-spin relaxation time (T1) to the <span class="hlt">electron</span>-phonon relaxation rate is in quantitative agreement with the Elliot-Yafet scaling, an evidence that spin-relaxation in Al grains is driven by the spin-orbit interaction. The spin-relaxation time of the low-lying excited states is T1 ≈ 0.7 mus and 0.1 mus in two samples, showing that <span class="hlt">electron</span> spin in a metallic grain could be a potential candidate for quantum information research. We also present measurements of mesoscopic resistance fluctuations in cobalt nanoparticles at low temperature and study how the fluctuations with bias voltage, bias fingerprints, respond to magnetization-reversal processes. Bias fingerprints rearrange when domains are nucleated or annihilated. The domain wall causes an <span class="hlt">electron</span> wave function-phase shift of ˜5 pi. The phase shift is not caused by the Aharonov-Bohm effect; we explain how it arises from the mistracking effect, where <span class="hlt">electron</span> spins lag in orientation with respect to the moments inside the domain wall. The dephasing length at low temperatures is only 30 nm, which is attributed to the large magnetocrystalline</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23385304','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23385304"><span id="translatedtitle">Nanogap structures: combining enhanced Raman spectroscopy and <span class="hlt">electronic</span> <span class="hlt">transport</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Natelson, Douglas; Li, Yajing; Herzog, Joseph B</p> <p>2013-04-21</p> <p>Surface-enhanced Raman spectroscopy (SERS) is an experimental tool for accessing vibrational and chemical information, down to the single molecule level. SERS typically relies on plasmon excitations in metal nanostructures to concentrate the incident radiation and to provide an enhanced photon density of states to couple emitted radiation to the far field. Many common SERS platforms involve metal nanoparticles to generate the required electromagnetic enhancements. Here we concentrate on an alternative approach, in which the relevant plasmon excitations are supported at a truly nanoscale gap between extended electrodes, rather than discrete subwavelength nanoparticles. The ability to fabricate precise gaps on demand, and in some cases to tune the gap size in situ, combined with the additional capability of simultaneous <span class="hlt">electronic</span> <span class="hlt">transport</span> measurements of the nanogap, provides access to information not previously available in standard SERS. We summarize the rich plasmonic physics at work in these extended systems and highlight the recent state of the art including tip-enhanced Raman spectroscopy (TERS) and the application of mechanical break junctions and electromigrated junctions. We describe in detail how we have performed in situ gap-enhanced Raman measurements of molecular-scale junctions while simultaneously subjecting these structures to <span class="hlt">electronic</span> <span class="hlt">transport</span>. These extended electrode structures allow us to study the pumping of vibrational modes by the flow of tunneling <span class="hlt">electrons</span>, as well as the shifting of vibrational energies due to the applied bias. These experiments extend SERS into a tool for examining fundamental processes of dissipation, and provide insight into the mechanisms behind SERS spectral diffusion. We conclude with a brief discussion of future directions. PMID:23385304</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EL.....9935003N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EL.....9935003N"><span id="translatedtitle"><span class="hlt">Transport</span> of <span class="hlt">electrons</span> in Ar/H2 mixtures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nikitović, Ž.; Stojanović, V.; Petrović, Z. Lj.</p> <p>2012-08-01</p> <p>In this work we present <span class="hlt">transport</span> coefficients for <span class="hlt">electrons</span> in Ar/H2 mixtures for the conditions used in plasma-assisted technologies for semiconductor production, i.e., in moderate and very high E/N. We used a two-term numerical solution of the Boltzmann equation at the lowest E/N (E is the electric field; N is the gas density) and correspondingly at the lowest mean energies. We also use the Monte Carlo simulation technique at moderate and high E/N. We show that a good agreement with experimental data exists for low and moderate E/N and that based on the tests for pure H2 and Ar we can model properly the swarm properties at high E/N. For the conditions of very high electric fields runaway peaks develop in the <span class="hlt">electron</span> energy distribution function and appreciable contribution of backscattered high-energy <span class="hlt">electrons</span> produces additional emission of Hα emission close to the anode (made of stainless steel). Results are obtained for abundances of H2 from 1% to 30%, which are necessary in kinetic models for this mixture in a number of applications.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012APS..MARH13012H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012APS..MARH13012H&link_type=ABSTRACT"><span id="translatedtitle">Hot <span class="hlt">electron</span> spin <span class="hlt">transport</span> in C60 fullerene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hueso, Luis Eduardo; Gobbi, Marco; Bedoya-Pinto, Amilcar; Golmar, Federico; Llopis, Roger; Casanova, Felix</p> <p>2012-02-01</p> <p>Carbon-based molecular materials are interesting for spin <span class="hlt">transport</span> application mainly due to their small sources of spin relaxation [1]. However, spin coherence lengths reported in many molecular films do not exceed a few tens of nanometers [2]. In this work we will present results showing how hot spin-polarized <span class="hlt">electrons</span> injected well above the Fermi level in C60 fullerene films travel coherently for hundreds of nanometers. We fabricated hot-<span class="hlt">electron</span> vertical transistors, in which the current created across an Al/Al2O3 junction is polarized by a metallic Co/Cu/Py spin valve trilayer and subsequently injected in the molecular thin film. This geometry allows us to determine the energy level alignment at each interface between different materials. Moreover, the collector magnetocurrent excess 85%, even for C60 films thicknesses of 300 nm. We believe these results show the importance of hot spin-polarized <span class="hlt">electron</span> injection and propagation in molecular materials. [1] V. Dediu, L.E. Hueso, I. Bergenti, C. Taliani, Nature Mater. 8, 707 (2009) [2] M. Gobbi, F. Golmar, R. Llopis, F. Casanova, L.E. Hueso, Adv. Mater. 23, 1609 (2011)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.720a2046D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.720a2046D"><span id="translatedtitle">Parallel processing implementation for the coupled <span class="hlt">transport</span> of photons and <span class="hlt">electrons</span> using OpenMP</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Doerner, Edgardo</p> <p>2016-05-01</p> <p>In this work the use of OpenMP to implement the parallel processing of the Monte Carlo (MC) simulation of the coupled <span class="hlt">transport</span> for photons and <span class="hlt">electrons</span> is presented. This implementation was carried out using a modified EGSnrc platform which enables the use of the Microsoft Visual Studio 2013 (VS2013) <span class="hlt">environment</span>, together with the developing tools available in the Intel Parallel Studio XE 2015 (XE2015). The performance study of this new implementation was carried out in a desktop PC with a multi-core CPU, taking as a reference the performance of the original platform. The results were satisfactory, both in terms of scalability as parallelization efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22262617','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22262617"><span id="translatedtitle"><span class="hlt">Electron-electron</span> interaction, weak localization and spin valve effect in vertical-<span class="hlt">transport</span> graphene devices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Long, Mingsheng; Gong, Youpin; Wei, Xiangfei; Zhu, Chao; Xu, Jianbao; Liu, Ping; Guo, Yufen; Li, Weiwei; Liu, Liwei; Liu, Guangtong</p> <p>2014-04-14</p> <p>We fabricated a vertical structure device, in which graphene is sandwiched between two asymmetric ferromagnetic electrodes. The measurements of <span class="hlt">electron</span> and spin <span class="hlt">transport</span> were performed across the combined channels containing the vertical and horizontal components. The presence of <span class="hlt">electron-electron</span> interaction (EEI) was found not only at low temperatures but also at moderate temperatures up to ∼120 K, and EEI dominates over weak localization (WL) with and without applying magnetic fields perpendicular to the sample plane. Moreover, spin valve effect was observed when magnetic filed is swept at the direction parallel to the sample surface. We attribute the EEI and WL surviving at a relatively high temperature to the effective suppress of phonon scattering in the vertical device structure. The findings open a way for studying quantum correlation at relatively high temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApPhL.107o3504B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApPhL.107o3504B"><span id="translatedtitle">Density-dependent <span class="hlt">electron</span> <span class="hlt">transport</span> and precise modeling of GaN high <span class="hlt">electron</span> mobility transistors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bajaj, Sanyam; Shoron, Omor F.; Park, Pil Sung; Krishnamoorthy, Sriram; Akyol, Fatih; Hung, Ting-Hsiang; Reza, Shahed; Chumbes, Eduardo M.; Khurgin, Jacob; Rajan, Siddharth</p> <p>2015-10-01</p> <p>We report on the direct measurement of two-dimensional sheet charge density dependence of <span class="hlt">electron</span> <span class="hlt">transport</span> in AlGaN/GaN high <span class="hlt">electron</span> mobility transistors (HEMTs). Pulsed IV measurements established increasing <span class="hlt">electron</span> velocities with decreasing sheet charge densities, resulting in saturation velocity of 1.9 × 107 cm/s at a low sheet charge density of 7.8 × 1011 cm-2. An optical phonon emission-based <span class="hlt">electron</span> velocity model for GaN is also presented. It accommodates stimulated longitudinal optical (LO) phonon emission which clamps the <span class="hlt">electron</span> velocity with strong <span class="hlt">electron</span>-phonon interaction and long LO phonon lifetime in GaN. A comparison with the measured density-dependent saturation velocity shows that it captures the dependence rather well. Finally, the experimental result is applied in TCAD-based device simulator to predict DC and small signal characteristics of a reported GaN HEMT. Good agreement between the simulated and reported experimental results validated the measurement presented in this report and established accurate modeling of GaN HEMTs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22482256','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22482256"><span id="translatedtitle">Density-dependent <span class="hlt">electron</span> <span class="hlt">transport</span> and precise modeling of GaN high <span class="hlt">electron</span> mobility transistors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bajaj, Sanyam Shoron, Omor F.; Park, Pil Sung; Krishnamoorthy, Sriram; Akyol, Fatih; Hung, Ting-Hsiang; Reza, Shahed; Chumbes, Eduardo M.; Khurgin, Jacob; Rajan, Siddharth</p> <p>2015-10-12</p> <p>We report on the direct measurement of two-dimensional sheet charge density dependence of <span class="hlt">electron</span> <span class="hlt">transport</span> in AlGaN/GaN high <span class="hlt">electron</span> mobility transistors (HEMTs). Pulsed IV measurements established increasing <span class="hlt">electron</span> velocities with decreasing sheet charge densities, resulting in saturation velocity of 1.9 × 10{sup 7 }cm/s at a low sheet charge density of 7.8 × 10{sup 11 }cm{sup −2}. An optical phonon emission-based <span class="hlt">electron</span> velocity model for GaN is also presented. It accommodates stimulated longitudinal optical (LO) phonon emission which clamps the <span class="hlt">electron</span> velocity with strong <span class="hlt">electron</span>-phonon interaction and long LO phonon lifetime in GaN. A comparison with the measured density-dependent saturation velocity shows that it captures the dependence rather well. Finally, the experimental result is applied in TCAD-based device simulator to predict DC and small signal characteristics of a reported GaN HEMT. Good agreement between the simulated and reported experimental results validated the measurement presented in this report and established accurate modeling of GaN HEMTs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12535543','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12535543"><span id="translatedtitle">On the application of quantum <span class="hlt">transport</span> theory to <span class="hlt">electron</span> sources.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jensen, Kevin L</p> <p>2003-01-01</p> <p><span class="hlt">Electron</span> sources (e.g., field emitter arrays, wide band-gap (WBG) semiconductor materials and coatings, carbon nanotubes, etc.) seek to exploit ballistic <span class="hlt">transport</span> within the vacuum after emission from microfabricated structures. Regardless of kind, all sources strive to minimize the barrier to <span class="hlt">electron</span> emission by engineering material properties (work function/<span class="hlt">electron</span> affinity) or physical geometry (field enhancement) of the cathode. The unique capabilities of cold cathodes, such as instant ON/OFF performance, high brightness, high current density, large transconductance to capacitance ratio, cold emission, small size and/or low voltage operation characteristics, commend their use in several advanced devices when physical size, weight, power consumption, beam current, and pulse repletion frequency are important, e.g., RF power amplifier such as traveling wave tubes (TWTs) for radar and communications, electrodynamic tethers for satellite deboost/reboost, and electric propulsion systems such as Hall thrusters for small satellites. The theoretical program described herein is directed towards models to evaluate emission current from <span class="hlt">electron</span> sources (in particular, emission from WBG and Spindt-type field emitter) in order to assess their utility, capabilities and performance characteristics. Modeling efforts particularly include: band bending, non-linear and resonant (Poole-Frenkel) potentials, the extension of one-dimensional theory to multi-dimensional structures, and emission site statistics due to variations in geometry and the presence of adsorbates. Two particular methodologies, namely, the modified Airy approach and metal-semiconductor statistical hyperbolic/ellipsoidal model, are described in detail in their present stage of development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12322742','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12322742"><span id="translatedtitle">Organic nature of colloidal actinides <span class="hlt">transported</span> in surface water <span class="hlt">environments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Santschi, Peter H; Roberts, Kimberly A; Guo, Laodong</p> <p>2002-09-01</p> <p>Elevated levels of (239,240)Pu and 241Am have been present in surficial soils of the Rocky Flats Environmental Technology Site (RFETS), CO, since the 1960s, when soils were locally contaminated in the 1960s by leaking drums stored on the 903 Pad. Further dispersion of contaminated soil particles was by wind and water. From 1998 until 2001, we examined actinide ((239,240)Pu and 241Am) concentrations and phase speciation in the surface <span class="hlt">environment</span> at RFETS through field studies and laboratory experiments. Measurements of total (239,240)Pu and 241Am concentrations in storm runoff and pond discharge samples, collected during spring and summer times in 1998-2000, demonstrate that most of the (239,240)Pu and 241Am <span class="hlt">transported</span> from contaminated soils to streams occurred in the particulate (> or = 0.45 microm; 40-90%) and colloidal (approximately 2 nm or 3 kDa to 0.45 microm; 10-60%) phases. Controlled laboratory investigations of soil resuspension, which simulated storm and erosion events, confirmed that most of the Pu in the 0.45 microm filter-passing phase was in the colloidal phase (> or = 80%) and that remobilization of colloid-bound Pu during soil erosion events can be greatly enhanced by humic and fulvic acids present in these soils. Most importantly, isoelectric focusing experiments of radiolabeled colloidal matter extracted from RFETS soils revealed that colloidal Pu is in the four-valent state and is mostly associated with a negatively charged organic macromolecule with a pH(IEP) of 3.1 and a molecular weight of 10-15 kDa, rather than with the more abundant inorganic (iron oxide and clay) colloids. This finding has important ramifications for possible remediation, erosion controls, and land-management strategies. PMID:12322742</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20110008233&hterms=proton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dproton','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20110008233&hterms=proton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dproton"><span id="translatedtitle">A Deterministic <span class="hlt">Electron</span>, Photon, Proton and Heavy Ion Radiation <span class="hlt">Transport</span> Suite for the Study of the Jovian System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Norman, Ryan B.; Badavi, Francis F.; Blattnig, Steve R.; Atwell, William</p> <p>2011-01-01</p> <p>A deterministic suite of radiation <span class="hlt">transport</span> codes, developed at NASA Langley Research Center (LaRC), which describe the <span class="hlt">transport</span> of <span class="hlt">electrons</span>, photons, protons, and heavy ions in condensed media is used to simulate exposures from spectral distributions typical of <span class="hlt">electrons</span>, protons and carbon-oxygen-sulfur (C-O-S) trapped heavy ions in the Jovian radiation <span class="hlt">environment</span>. The particle <span class="hlt">transport</span> suite consists of a coupled <span class="hlt">electron</span> and photon deterministic <span class="hlt">transport</span> algorithm (CEPTRN) and a coupled light particle and heavy ion deterministic <span class="hlt">transport</span> algorithm (HZETRN). The primary purpose for the development of the <span class="hlt">transport</span> suite is to provide a means for the spacecraft design community to rapidly perform numerous repetitive calculations essential for <span class="hlt">electron</span>, proton and heavy ion radiation exposure assessments in complex space structures. In this paper, the radiation <span class="hlt">environment</span> of the Galilean satellite Europa is used as a representative boundary condition to show the capabilities of the <span class="hlt">transport</span> suite. While the <span class="hlt">transport</span> suite can directly access the output <span class="hlt">electron</span> spectra of the Jovian <span class="hlt">environment</span> as generated by the Jet Propulsion Laboratory (JPL) Galileo Interim Radiation <span class="hlt">Electron</span> (GIRE) model of 2003; for the sake of relevance to the upcoming Europa Jupiter System Mission (EJSM), the 105 days at Europa mission fluence energy spectra provided by JPL is used to produce the corresponding dose-depth curve in silicon behind an aluminum shield of 100 mils ( 0.7 g/sq cm). The <span class="hlt">transport</span> suite can also accept ray-traced thickness files from a computer-aided design (CAD) package and calculate the total ionizing dose (TID) at a specific target point. In that regard, using a low-fidelity CAD model of the Galileo probe, the <span class="hlt">transport</span> suite was verified by comparing with Monte Carlo (MC) simulations for orbits JOI--J35 of the Galileo extended mission (1996-2001). For the upcoming EJSM mission with a potential launch date of 2020, the <span class="hlt">transport</span> suite is used to compute</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1170451','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1170451"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> in pure and substituted iron oxyhydroxides by small-polaron migration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Alexandrov, Vitali Y.; Rosso, Kevin M.</p> <p>2014-08-12</p> <p>Iron oxyhydroxides (FeOOH) are common crystalline forms of iron that play a critical role in technology and the natural <span class="hlt">environment</span> via a variety of important reduction-oxidation reactions, including electrical semiconduction as an aspect. However, a basic understanding of the <span class="hlt">electron</span> <span class="hlt">transport</span> properties of these systems is still lacking. We examine the <span class="hlt">electron</span> mobility in goethite (α-FeOOH), akaganéite (β-FeOOH), and lepidocrocite (γ -FeOOH) polymorphs by means of density functional theory based (DFT+U) calculations.We show that room temperature charge <span class="hlt">transport</span> should be dominated by the small-polaron hopping type, and that the attendant mobility should be highest for pure goethite and akaganéite. Hopping pathways through the various lattices are discussed in terms of individual <span class="hlt">electron</span> exchange steps and rates for each. Given the usual occurrence of compositional impurities in natural iron oxyhydroxides, we also investigate the effect of common stoichiometric defects on the <span class="hlt">electron</span> hopping activation energies such as Al and Cr substitutional cations in goethite, and Cl anions in the channels of akaganéite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22420075','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22420075"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> in pure and substituted iron oxyhydroxides by small-polaron migration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Alexandrov, Vitaly Rosso, Kevin M.</p> <p>2014-06-21</p> <p>Iron oxyhydroxides (FeOOH) are common crystalline forms of iron that play a critical role in technology and the natural <span class="hlt">environment</span> via a variety of important reduction-oxidation reactions, including electrical semiconduction as an aspect. However, a basic understanding of the <span class="hlt">electron</span> <span class="hlt">transport</span> properties of these systems is still lacking. We examine the <span class="hlt">electron</span> mobility in goethite (α-FeOOH), akaganéite (β-FeOOH), and lepidocrocite (γ-FeOOH) polymorphs by means of density functional theory based (DFT+U) calculations. We show that room temperature charge <span class="hlt">transport</span> should be dominated by the small-polaron hopping type, and that the attendant mobility should be highest for pure goethite and akaganéite. Hopping pathways through the various lattices are discussed in terms of individual <span class="hlt">electron</span> exchange steps and rates for each. Given the usual occurrence of compositional impurities in natural iron oxyhydroxides, we also investigate the effect of common stoichiometric defects on the <span class="hlt">electron</span> hopping activation energies such as Al and Cr substitutional cations in goethite, and Cl anions in the channels of akaganéite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1728b0669B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1728b0669B"><span id="translatedtitle">Effect of doping on the <span class="hlt">electron</span> <span class="hlt">transport</span> in polyfluorene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bajpai, Manisha; Srivastava, Ritu; Dhar, Ravindra; Tiwari, R. S.</p> <p>2016-05-01</p> <p>In this paper, <span class="hlt">electron</span> <span class="hlt">transport</span> of pure and DMC doped polyfluorne (PF) films have been studied at various doping concentrations. Pure films show space charge limited conduction with field and temperature dependent mobility. The J-V characteristics of doped PF were ohmic at low voltages due to thermally released carriers from dopant states. At higher voltages the current density increases nonlinearly due to field dependent mobility and carrier concentration thereby filling of tail states of HOMO of the host. The conductivity of doped fims were analyzed using the Unified Gaussian Disorder Model (UGDM). The carrier concentration obtained from the fitting show a non-linear dependence on doping concentration which may be due to a combined effect of thermally activated carrier generation and increased carrier mobility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARC26001B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARC26001B"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">Transport</span> Simulations of 4-Terminal Crossed Graphene Nanoribbons Devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brandimarte, Pedro; Papior, Nick R.; Engelund, Mads; Garcia-Lekue, Aran; Frederiksen, Thomas; Sánchez-Portal, Daniel</p> <p></p> <p>Recently, it has been reported theoretically a current switching mechanism by voltage control in a system made by two perpendicular 14-armchair graphene nanoribbons (GNRs). In order to investigate the possibilities of using crossed GNRs as ON/OFF devices, we have studied their <span class="hlt">electronic</span> and <span class="hlt">transport</span> properties as function structural parameters determining the crossing. Our calculations were performed with TranSIESTA code, which has been recently generalized to consider N >= 1 arbitrarily distributed electrodes at finite bias. We find that the transmission along each individual GNR and among them strongly depends on the stacking. For a 60° rotation angle, the lattice matching in the crossing region provokes a strong scattering effect that translates into an increased interlayer transmission. FP7 FET-ICT PAMS-project (European Commission, contract 610446), MINECO (Grant MAT2013-46593-C6-2-P) and Basque Dep. de Educación, UPV/EHU (Grant IT-756-13).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22492133','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22492133"><span id="translatedtitle">Conformation dependent <span class="hlt">electronic</span> <span class="hlt">transport</span> in a DNA double-helix</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kundu, Sourav Karmakar, S. N.</p> <p>2015-10-15</p> <p>We present a tight-binding study of conformation dependent <span class="hlt">electronic</span> <span class="hlt">transport</span> properties of DNA double-helix including its helical symmetry. We have studied the changes in the localization properties of DNA as we alter the number of stacked bases within every pitch of the double-helix keeping fixed the total number of nitrogen bases within the DNA molecule. We take three DNA sequences, two of them are periodic and one is random and observe that in all the cases localization length increases as we increase the radius of DNA double-helix i.e., number of nucleobases within a pitch. We have also investigated the effect of backbone energetic on the I-V response of the system and found that in presence of helical symmetry, depending on the interplay of conformal variation and disorder, DNA can be found in either metallic, semiconducting and insulating phases, as observed experimentally.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ApPhL..87w3509G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ApPhL..87w3509G"><span id="translatedtitle">Device structure for <span class="hlt">electronic</span> <span class="hlt">transport</span> through individual molecules using nanoelectrodes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghosh, Subhasis; Halimun, Henny; Mahapatro, Ajit Kumar; Choi, Jaewon; Lodha, Saurabh; Janes, David</p> <p>2005-12-01</p> <p>We present a simple and reliable method for making electrical contacts to small organic molecules with thiol endgroups. Nanometer-scale gaps between metallic electrodes have been fabricated by passing a large current through a lithographically-patterned Au-line with appropriate thickness. Under appropriate conditions, the passage of current breaks the Au-line, creating two opposite facing electrodes separated by a gap comparable to the length of small organic molecules. Current-voltage characteristics have been measured both before and after deposition of short organic molecules. The resistance of single 1,4-benzenedithiol and 1,4-bezenedimethanedithiol molecules were found to be 9MΩ and 26MΩ, respectively. The experimental results indicate strong <span class="hlt">electronic</span> coupling to the contacts and are discussed using a relatively simple model of mesoscopic <span class="hlt">transport</span>. The use of electrodes formed on an insulating surface by lithography and electromigration provides a stable structure suitable for integrated circuit applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1009202','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1009202"><span id="translatedtitle">Hot <span class="hlt">Electron</span> Generation and <span class="hlt">Transport</span> Using K(alpha) Emission</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Akli, K U; Stephens, R B; Key, M H; Bartal, T; Beg, F N; Chawla, S; Chen, C D; Fedosejevs, R; Freeman, R R; Friesen, H; Giraldez, E; Green, J S; Hey, D S; Higginson, D P; Hund, J; Jarrott, L C; Kemp, G E; King, J A; Kryger, A; Lancaster, K; LePape, S; Link, A; Ma, T; Mackinnon, A J; MacPhee, A G; McLean, H S; Murphy, C; Norreys, P A; Ovchinnikov, V; Patel, P K; Ping, Y; Sawada, H; Schumacher, D; Theobald, W; Tsui, Y Y; Van Woerkom, L D; Wei, M S; Westover, B; Yabuuchi, T</p> <p>2009-10-15</p> <p>We have conducted experiments on both the Vulcan and Titan laser facilities to study hot <span class="hlt">electron</span> generation and <span class="hlt">transport</span> in the context of fast ignition. Cu wires attached to Al cones were used to investigate the effect on coupling efficiency of plasma surround and the pre-formed plasma inside the cone. We found that with thin cones 15% of laser energy is coupled to the 40{micro}m diameter wire emulating a 40{micro}m fast ignition spot. Thick cone walls, simulating plasma in fast ignition, reduce coupling by x4. An increase of prepulse level inside the cone by a factor of 50 reduces coupling by a factor of 3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJB...89..191Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJB...89..191Z"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> properties of a quinone-based molecular switch</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zheng, Ya-Peng; Bian, Bao-An; Yuan, Pei-Pei</p> <p>2016-09-01</p> <p>In this paper, we carried out first-principles calculations based on density functional theory and non-equilibrium Green's function to investigate the <span class="hlt">electronic</span> <span class="hlt">transport</span> properties of a quinone-based molecule sandwiched between two Au electrodes. The molecular switch can be reversibly switched between the reduced hydroquinone (HQ) and oxidized quinone (Q) states via redox reactions. The switching behavior of two forms is analyzed through their I- V curves, transmission spectra and molecular projected self-consistent Hamiltonian at zero bias. Then we discuss the transmission spectra of the HQ and Q forms at different bias, and explain the oscillation of current according to the transmission eigenstates of LUMO energy level for Q form. The results suggest that this kind of a quinone-based molecule is usable as one of the good candidates for redox-controlled molecular switches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011PhyE...43.1655S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011PhyE...43.1655S&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> characteristics in silicon nanotube field-effect transistors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shan, Guangcun; Wang, Yu; Huang, Wei</p> <p>2011-07-01</p> <p>The successful synthesis of silicon nanotubes (SiNTs) has been reported, making these nanostructures a new novel candidate for future nanodevices. By self-consistently solving the Poisson equations using the non-equilibrium Green's function (NEGF) formalism, we investigate the <span class="hlt">electronic</span> <span class="hlt">transport</span> and the role of gate bias in affecting the drive current of single-walled silicon nanotube (SW-SiNT) field-effect transistors (FETs). By comparison of a SW-CNT FET, it is found that the SW-SiNT with a high- k HfO gate oxide is a promising candidate for nanotube transistor with better performance. The results discussed here would serve as a versatile and powerful guideline for future experimental studies of SW-SiNT-based transistor with the purpose of exploring device application for nanoelectronics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.F5008Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.F5008Q"><span id="translatedtitle"><span class="hlt">Electronic</span> measurement of strain effects on spin <span class="hlt">transport</span> in silicon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qing, Lan; Tinkey, Holly; Appelbaum, Ian</p> <p></p> <p>Spin <span class="hlt">transport</span> in silicon is limited by the Elliott-Yafet spin relaxation mechanism, which is driven by scattering between degenerate conduction band valleys. Mechanical strain along a valley axis partially breaks this degeneracy, and will ultimately quench intervalley spin relaxation for transitions between states on orthogonal axes. Using a custom-designed and constructed strain probe, we study the effects of uniaxial compressive strain along the < 100 > direction on ballistic tunnel junction devices used to inject spin-polarized <span class="hlt">electrons</span> into silicon. The effects of strain-induced valley splitting will be presented and compared to our theoretical model. This work is supported by the Office of Naval Research under Contract No. N000141410317, the National Science Foundation under Contract No. ECCS-1231855, the Defense Threat Reduction Agency under Contract No. HDTRA1-13-1-0013, and the Maryland NanoCenter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/984468','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/984468"><span id="translatedtitle">Anomalous <span class="hlt">Electron</span> <span class="hlt">Transport</span> Due to Multiple High Frequency Beam Ion Driven Alfven Eigenmode</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gorelenkov, N. N.; Stutman, D.; Tritz, K.; Boozer, A.; Delgardo-Aparicio, L.; Fredrickson, E.; Kaye, S.; White, R.</p> <p>2010-07-13</p> <p>We report on the simulations of recently observed correlations of the core <span class="hlt">electron</span> <span class="hlt">transport</span> with the sub-thermal ion cyclotron frequency instabilities in low aspect ratio plasmas of the National Spherical Torus Experiment (NSTX). In order to model the <span class="hlt">electron</span> <span class="hlt">transport</span> of the guiding center code ORBIT is employed. A spectrum of test functions of multiple core localized Global shear Alfven Eigenmode (GAE) instabilities based on a previously developed theory and experimental observations is used to examine the <span class="hlt">electron</span> <span class="hlt">transport</span> properties. The simulations exhibit thermal <span class="hlt">electron</span> <span class="hlt">transport</span> induced by <span class="hlt">electron</span> drift orbit stochasticity in the presence of multiple core localized GAE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT.......167B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT.......167B"><span id="translatedtitle">Characterization of ionic <span class="hlt">transport</span> in polymer and <span class="hlt">electronic</span> <span class="hlt">transport</span> in disordered selenium and ceramic materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bandyopadhyay, Subhasish</p> <p></p> <p>In this thesis, the properties of <span class="hlt">electronic</span> conduction in vanadium (donor) and scandium (acceptor) doped Ba0.7Sr0.3TiO3 ceramics, amorphous Selenium and ionic conduction in polyester polyol based polyurethane have been investigated. The leakage current of bulk vanadium (donor) and scandium (acceptor) doped Ba0.7Sr0.3TiO3 ceramics structures measured using gold electrical contacts have been characterized and analyzed. Vanadium doping reduces the ohmic leakage current that dominates the <span class="hlt">transport</span> characteristics up to 5 kV/cm. The Arrhenius activation energy is 0.18, 0.20 and 0.23 eV for 1, 2 and 4 at % V-doped samples, respectively. Above this field, the current-voltage characteristics exhibit discontinuous current transitions associated with trap filling by <span class="hlt">electronic</span> carriers. At higher fields, trap controlled space charge limited conduction (SCLC) is observed with an effective mobility of 4+/-1x10-7 cm2/V s, characteristic of <span class="hlt">electronic</span> <span class="hlt">transport</span> process that involves quasi equilibrium between conduction in the band and trapping. In contrast, the leakage current of Sc-doped samples increases with impurity concentration and exhibits a 0.60 eV activation energy. In this case, the limiting current conduction mechanism is the <span class="hlt">transport</span> of holes over the electrostatic barrier at grain boundaries. Comparison of these results to those on similarly-doped homoepitaxial SrTiO3 thin-films deposited on single-crystal and bicrystal substrates helped to identify the characteristics of <span class="hlt">transport</span> in the bulk and across grain boundaries for this class of materials. Electrical, thermal and Li <span class="hlt">transport</span> properties have been measured for polyester polyol and isocyanate-based polyurethanes doped with Lithium trifluoromethanesulfonimide (LiTFSI) and Lithium perchlorate (LiClO4) Electrical conductivities are estimated at 10-5--10-6 S/cm near 300 K. The conductivities show Vogel-Tammann-Fulcher (VTF) behavior over a wide temperature ranges. Differential scanning calorimetry (DSC) shows</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PPCF...58e5002K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PPCF...58e5002K"><span id="translatedtitle">Simple predictive <span class="hlt">electron</span> <span class="hlt">transport</span> models applied to sawtoothing plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, D.; Merle, A.; Sauter, O.; Goodman, T. P.</p> <p>2016-05-01</p> <p>In this work, we introduce two simple <span class="hlt">transport</span> models to evaluate the time evolution of <span class="hlt">electron</span> temperature and density profiles during sawtooth cycles (i.e. over a sawtooth period time-scale). Since the aim of these simulations is to estimate reliable profiles within a short calculation time, two simplified ad-hoc models have been developed. The goal for these models is to rely on a few easy-to-check free parameters, such as the confinement time scaling factor and the profiles’ averaged scale-lengths. Due to the simplicity and short calculation time of the models, it is expected that these models can also be applied to real-time <span class="hlt">transport</span> simulations. We show that it works well for Ohmic and EC heated L- and H-mode plasmas. The differences between these models are discussed and we show that their predictive capabilities are similar. Thus only one model is used to reproduce with simulations the results of sawtooth control experiments on the TCV tokamak. For the sawtooth pacing, the calculated time delays between the EC power off and sawtooth crash time agree well with the experimental results. The map of possible locking range is also well reproduced by the simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22493896','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22493896"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> in molecular junctions with graphene as protecting layer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hüser, Falco; Solomon, Gemma C.</p> <p>2015-12-07</p> <p>We present ab initio <span class="hlt">transport</span> calculations for molecular junctions that include graphene as a protecting layer between a single molecule and gold electrodes. This vertical setup has recently gained significant interest in experiment for the design of particularly stable and reproducible devices. We observe that the signals from the molecule in the <span class="hlt">electronic</span> transmission are overlayed by the signatures of the graphene sheet, thus raising the need for a reinterpretation of the transmission. On the other hand, we see that our results are stable with respect to various defects in the graphene. For weakly physiosorbed molecules, no signs of interaction with the graphene are evident, so the <span class="hlt">transport</span> properties are determined by offresonant tunnelling between the gold leads across an extended structure that includes the molecule itself and the additional graphene layer. Compared with pure gold electrodes, calculated conductances are about one order of magnitude lower due to the increased tunnelling distance. Relative differences upon changing the end group and the length of the molecule on the other hand, are similar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JChPh.143u4302H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JChPh.143u4302H"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> in molecular junctions with graphene as protecting layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hüser, Falco; Solomon, Gemma C.</p> <p>2015-12-01</p> <p>We present ab initio <span class="hlt">transport</span> calculations for molecular junctions that include graphene as a protecting layer between a single molecule and gold electrodes. This vertical setup has recently gained significant interest in experiment for the design of particularly stable and reproducible devices. We observe that the signals from the molecule in the <span class="hlt">electronic</span> transmission are overlayed by the signatures of the graphene sheet, thus raising the need for a reinterpretation of the transmission. On the other hand, we see that our results are stable with respect to various defects in the graphene. For weakly physiosorbed molecules, no signs of interaction with the graphene are evident, so the <span class="hlt">transport</span> properties are determined by offresonant tunnelling between the gold leads across an extended structure that includes the molecule itself and the additional graphene layer. Compared with pure gold electrodes, calculated conductances are about one order of magnitude lower due to the increased tunnelling distance. Relative differences upon changing the end group and the length of the molecule on the other hand, are similar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9458E..0HA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9458E..0HA"><span id="translatedtitle">Cyber warfare and <span class="hlt">electronic</span> warfare integration in the operational <span class="hlt">environment</span> of the future: cyber <span class="hlt">electronic</span> warfare</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Askin, Osman; Irmak, Riza; Avsever, Mustafa</p> <p>2015-05-01</p> <p>For the states with advanced technology, effective use of <span class="hlt">electronic</span> warfare and cyber warfare will be the main determining factor of winning a war in the future's operational <span class="hlt">environment</span>. The developed states will be able to finalize the struggles they have entered with a minimum of human casualties and minimum cost thanks to high-tech. Considering the increasing number of world economic problems, the development of human rights and humanitarian law it is easy to understand the importance of minimum cost and minimum loss of human. In this paper, cyber warfare and <span class="hlt">electronic</span> warfare concepts are examined in conjunction with the historical development and the relationship between them is explained. Finally, assessments were carried out about the use of cyber <span class="hlt">electronic</span> warfare in the coming years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007ChPhL..24.1042O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007ChPhL..24.1042O"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">Transport</span> in Molecular Junction Based on C20 Cages</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ouyang, Fang-Ping; Xu, Hui</p> <p>2007-04-01</p> <p>Choosing closed-ended armchair (5, 5) single-wall carbon nanotubes (CCNTs) as electrodes, we investigate the <span class="hlt">electron</span> <span class="hlt">transport</span> properties across an all-carbon molecular junction consisting of C20 molecules suspended between two semi-infinite carbon nanotubes. It is shown that the conductances are quite sensitive to the number of C20 molecules between electrodes for both configuration CF1 and double-bonded models: the conductances of C20 dimers are markedly smaller than those of monomers. The physics is that incident <span class="hlt">electrons</span> easily pass the C20 molecules and are predominantly scattered at the C20-C20 junctions. Moreover, we study the doping effect of such molecular junction by doping nitrogen atoms substitutionally. The bonding property of the molecular junction with configuration CF1 has been analysed by calculating the Mulliken atomic charges. Our results have revealed that the C atoms in N-doped junctions are more ionic than those in pure-carbon ones, leading to the fact that N-doped junctions have relatively large conductance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15328348','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15328348"><span id="translatedtitle">Oxygen tolerance and coupling of mitochondrial <span class="hlt">electron</span> <span class="hlt">transport</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campian, Jian Li; Qian, Mingwei; Gao, Xueshan; Eaton, John W</p> <p>2004-11-01</p> <p>Oxygen is critical to aerobic metabolism, but excessive oxygen (hyperoxia) causes cell injury and death. An oxygen-tolerant strain of HeLa cells, which proliferates even under 80% O2, termed "HeLa-80," was derived from wild-type HeLa cells ("HeLa-20") by selection for resistance to stepwise increases of oxygen partial pressure. Surprisingly, antioxidant defenses and susceptibility to oxidant-mediated killing do not differ between these two strains of HeLa cells. However, under both 20 and 80% O2, intracellular reactive oxygen species (ROS) production is significantly (approximately 2-fold) less in HeLa-80 cells. In both cell lines the source of ROS is evidently mitochondrial. Although HeLa-80 cells consume oxygen at the same rate as HeLa-20 cells, they consume less glucose and produce less lactic acid. Most importantly, the oxygen-tolerant HeLa-80 cells have significantly higher cytochrome c oxidase activity (approximately 2-fold), which may act to deplete upstream <span class="hlt">electron</span>-rich intermediates responsible for ROS generation. Indeed, preferential inhibition of cytochrome c oxidase by treatment with n-methyl protoporphyrin (which selectively diminishes synthesis of heme a in cytochrome c oxidase) enhances ROS production and abrogates the oxygen tolerance of the HeLa-80 cells. Thus, it appears that the remarkable oxygen tolerance of these cells derives from tighter coupling of the <span class="hlt">electron</span> <span class="hlt">transport</span> chain. PMID:15328348</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21612067','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21612067"><span id="translatedtitle"><span class="hlt">Electron</span> Capture Reactions and Beta Decays in Steller <span class="hlt">Environments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Suzuki, T.; Mao, H.; Honma, M.; Yoshida, T.; Kajino, T.; Otsuka, T.</p> <p>2011-10-28</p> <p><span class="hlt">Electron</span> capture reactions on Ni and Co isotopes are investigated by shell model calculations in steller <span class="hlt">environments</span>. The capture rates depend sensitively on the distribution of the Gamow-Teller (GT) strength. The capture rates obtained by using GXPF1J Hamiltonian for fp-shell are found to be consistent with the rates obtained from experimental GT strength in {sup 58}Ni and {sup 60}Ni. Capture rates in Co isotopes, where there were large discrepancies among previous calculations, are also investigated. Beta decays of the N = 126 isotones are studied by shell model calculations taking into account both the GT and first-forbidden (FF) transitions. The FF transitions are found to be important to reduce the half-lives by twice to several times of those by the GT contributions only. Implications of the short half-lives of the waiting point nuclei on the r-process nucleosynthesis are discussed for various astrophysical conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title32-vol6/pdf/CFR-2013-title32-vol6-sec2001-23.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title32-vol6/pdf/CFR-2013-title32-vol6-sec2001-23.pdf"><span id="translatedtitle">32 CFR 2001.23 - Classification marking in the <span class="hlt">electronic</span> <span class="hlt">environment</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... <span class="hlt">environment</span>. 2001.23 Section 2001.23 National Defense Other Regulations Relating to National Defense... <span class="hlt">environment</span>. (a) General. Classified national security information in the <span class="hlt">electronic</span> <span class="hlt">environment</span> shall be: (1... <span class="hlt">electronic</span> <span class="hlt">environment</span> cannot be marked in this manner, a warning shall be applied to alert users that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title32-vol6/pdf/CFR-2014-title32-vol6-sec2001-23.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title32-vol6/pdf/CFR-2014-title32-vol6-sec2001-23.pdf"><span id="translatedtitle">32 CFR 2001.23 - Classification marking in the <span class="hlt">electronic</span> <span class="hlt">environment</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... <span class="hlt">environment</span>. 2001.23 Section 2001.23 National Defense Other Regulations Relating to National Defense... <span class="hlt">environment</span>. (a) General. Classified national security information in the <span class="hlt">electronic</span> <span class="hlt">environment</span> shall be: (1... <span class="hlt">electronic</span> <span class="hlt">environment</span> cannot be marked in this manner, a warning shall be applied to alert users that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title32-vol6/pdf/CFR-2012-title32-vol6-sec2001-23.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title32-vol6/pdf/CFR-2012-title32-vol6-sec2001-23.pdf"><span id="translatedtitle">32 CFR 2001.23 - Classification marking in the <span class="hlt">electronic</span> <span class="hlt">environment</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... <span class="hlt">environment</span>. 2001.23 Section 2001.23 National Defense Other Regulations Relating to National Defense... <span class="hlt">environment</span>. (a) General. Classified national security information in the <span class="hlt">electronic</span> <span class="hlt">environment</span> shall be: (1... <span class="hlt">electronic</span> <span class="hlt">environment</span> cannot be marked in this manner, a warning shall be applied to alert users that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title32-vol6/pdf/CFR-2011-title32-vol6-sec2001-23.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title32-vol6/pdf/CFR-2011-title32-vol6-sec2001-23.pdf"><span id="translatedtitle">32 CFR 2001.23 - Classification marking in the <span class="hlt">electronic</span> <span class="hlt">environment</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... <span class="hlt">environment</span>. 2001.23 Section 2001.23 National Defense Other Regulations Relating to National Defense... <span class="hlt">environment</span>. (a) General. Classified national security information in the <span class="hlt">electronic</span> <span class="hlt">environment</span> shall be: (1... <span class="hlt">electronic</span> <span class="hlt">environment</span> cannot be marked in this manner, a warning shall be applied to alert users that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/100296','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/100296"><span id="translatedtitle">Multigroup Boltzmann Fokker Planck <span class="hlt">electron</span>-photon <span class="hlt">transport</span> capability in MCNP{sup trademark}</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Adams, K.J.; Hart, M.</p> <p>1995-07-01</p> <p>The MCNP code system has a robust multigroup <span class="hlt">transport</span> capability which includes a multigroup Boltzmann-Fokker-Planck (MGBFP) <span class="hlt">transport</span> algorithm to perform coupled <span class="hlt">electron</span>-photon or other coupled charged and neutral particle <span class="hlt">transport</span> in either a forward or adjoint mode. This paper will discuss this capability and compare code results with other <span class="hlt">transport</span> codes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5590089','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5590089"><span id="translatedtitle">Flash spectroscopic characterization of photosynthetic <span class="hlt">electron</span> <span class="hlt">transport</span> in isolated heterocysts</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Houchins, J.P.; Hind, G.</p> <p>1983-07-01</p> <p><span class="hlt">Electron</span> <span class="hlt">transport</span> was studied in heterocysts of the filamentous cyanobacterium Anabaena 7120 using spectral and kinetic analysis of absorbance transients elicited by single turnover flashes. Consistent photosynthetic turnovers were observed only in the presence of an exogenous source of reductant; therefore measurements were routinely made under a gas phase containing H2. Prominent absorbance changes corresponding to the oxidation of cytochrome c (554 nm) and the reduction of cytochrome b563 (563 nm) were observed. Under the most reducing conditions (99% H2/1% O2) cytochrome b563 was partially reduced between flashes in a slow, dark reaction. At 10-15% O2, the slow, dark reduction of cytochrome b563 was eliminated. Cytochrome turnover ceased entirely at high O2 concentrations (30%) but was restored by the addition of 25 microM KCN, demonstrating an interaction between the photosynthetic and respiratory <span class="hlt">electron</span> transfer chains. Strobilurin A slowed the re-reduction of cytochrome c and eliminated the appearance of reduced cytochrome b563 by blocking <span class="hlt">electron</span> transfer between reduced plastoquinone and the cytochrome b/f complex. Inhibition at a second site was apparent with 2-(n-heptyl)-4-hydroxyquinoline N-oxide, which blocked the reoxidation of cytochrome b563 but had little effect on cytochrome c relaxation. In uncoupled heterocysts, the rates of cytochrome c re-reduction and cytochrome b563 reduction were equal. Additional unassigned absorbance changes at 475 nm, 515 nm, and 572 nm were partially characterized. No absorbance change corresponding to an electrochromic shift was observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060051442&hterms=built+environment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dbuilt%2Benvironment','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060051442&hterms=built+environment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dbuilt%2Benvironment"><span id="translatedtitle">Reconfiguration of Analog <span class="hlt">Electronics</span> for Extreme <span class="hlt">Environments</span>: Problem or Solution?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stoica, Adrian; Zebulum, Ricardo; Keymeulen, Didier; Guo, Xin</p> <p>2005-01-01</p> <p>This paper argues in favor of adaptive reconfiguration as a technique to expand the operational envelope of analog <span class="hlt">electronics</span> for extreme <span class="hlt">environments</span> (EE). In addition to hardening-by-process and hardening-by-design, "hardening-by-reconfiguration", when applicable, could be used to mitigate drifts, degradation, or damage on <span class="hlt">electronic</span> devices (chips) in EE, by using re-configurable devices and an adaptive self-reconfiguration of their circuit topology. Conventional circuit design exploits device characteristics within a certain temperature/radiation range; when that is exceeded, the circuit function degrades. On a reconfigurable device, although component parameters change in EE, as long as devices still operate, albeit degraded, a new circuit design, suitable for new parameter values, may be mapped into the reconfigurable structure to recover the initial circuit function. Partly degraded resources are still used, while completely damaged resources are bypassed. Designs suitable for various environmental conditions can be determined prior to operation or can be determined in-situ, by adaptive reconfiguration algorithms running on built-in digital controllers. Laboratory demonstrations of this technique were performed by JPL in several independent experiments in which bulk CMOS reconfigurable devices were exposed to, and degraded by, low temperatures (approx. 196 C), high temperatures (approx.300 C) or radiation (300kRad TID), and then recovered by adaptive reconfiguration using evolutionary search algorithms. Taking this technology from Technology Readiness Level (TRL) 3 to TRL 5 is the target of a current NASA project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......276M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......276M"><span id="translatedtitle"><span class="hlt">Transport</span> of Zinc Oxide Nanoparticles in a Simulated Gastric <span class="hlt">Environment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mayfield, Ryan T.</p> <p></p> <p>Recent years have seen a growing interest in the use of many types of nano sized materials in the consumer sector. Potential uses include encapsulation of nutrients, providing antimicrobial activity, altering texture, or changing bioavailability of nutrients. Engineered nanoparticles (ENP) possess properties that are different than larger particles made of the same constituents. Properties such as solubility, aggregation state, and toxicity can all be changed as a function of size. The gastric <span class="hlt">environment</span> is an important area for study of engineered nanoparticles because of the varied physical, chemical, and enzymatic processes that are prevalent there. These all have the potential to alter those properties of ENP that make them different from their bulk counterparts. The Human Gastric Simulator (HGS) is an advanced in vitro model that can be used to study many facets of digestion. The HGS consists of a plastic lining that acts as the stomach cavity with two sets of U-shaped arms on belts that provide the physical forces needed to replicate peristalsis. Altering the position of the arms or changing the speed of the motor which powers them allows one to tightly hone and replicate varied digestive conditions. Gastric juice, consisting of salts, enzymes, and acid levels which replicate physiological conditions, is introduced to the cavity at a controllable rate. The release of digested food from the lumen of simulated stomach is controlled by a peristaltic pump. The goal of the HGS is to accurately and repeatedly simulate human digestion. This study focused on introducing foods spiked with zinc oxide ENP and bulk zinc oxide into the HGS and then monitoring how the concentration of each changed at two locations in the HGS over a two hour period. The two locations chosen were the highest point in the lumen of the stomach, which represented the fundus, and a point just beyond the equivalent of the pylorus, which represented the antrum of the stomach. These points were</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PlPhR..42..713G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PlPhR..42..713G"><span id="translatedtitle">Simulation of <span class="hlt">electron</span> beam formation and <span class="hlt">transport</span> in a gas-filled <span class="hlt">electron</span>-optical system with a plasma emitter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grishkov, A. A.; Kornilov, S. Yu.; Rempe, N. G.; Shidlovskiy, S. V.; Shklyaev, V. A.</p> <p>2016-07-01</p> <p>The results of computer simulations of the <span class="hlt">electron</span>-optical system of an <span class="hlt">electron</span> gun with a plasma emitter are presented. The simulations are performed using the KOBRA3-INP, XOOPIC, and ANSYS codes. The results describe the <span class="hlt">electron</span> beam formation and <span class="hlt">transport</span>. The <span class="hlt">electron</span> trajectories are analyzed. The mechanisms of gas influence on the energy inhomogeneity of the beam and its current in the regions of beam primary formation, acceleration, and <span class="hlt">transport</span> are described. Recommendations for optimizing the <span class="hlt">electron</span>-optical system with a plasma emitter are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25255961','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25255961"><span id="translatedtitle">Basic concepts of quantum interference and <span class="hlt">electron</span> <span class="hlt">transport</span> in single-molecule <span class="hlt">electronics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lambert, C J</p> <p>2015-02-21</p> <p>This tutorial outlines the basic theoretical concepts and tools which underpin the fundamentals of phase-coherent <span class="hlt">electron</span> <span class="hlt">transport</span> through single molecules. The key quantity of interest is the transmission coefficient T(E), which yields the electrical conductance, current-voltage relations, the thermopower S and the thermoelectric figure of merit ZT of single-molecule devices. Since T(E) is strongly affected by quantum interference (QI), three manifestations of QI in single-molecules are discussed, namely Mach-Zehnder interferometry, Breit-Wigner resonances and Fano resonances. A simple MATLAB code is provided, which allows the novice reader to explore QI in multi-branched structures described by a tight-binding (Hückel) Hamiltonian. More generally, the strengths and limitations of materials-specific <span class="hlt">transport</span> modelling based on density functional theory are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.109o2904O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.109o2904O"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> and dielectric breakdown in silicon nitride using a charge <span class="hlt">transport</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ogden, Sean P.; Lu, Toh-Ming; Plawsky, Joel L.</p> <p>2016-10-01</p> <p>Silicon nitride is an important material used in the <span class="hlt">electronics</span> industry. As such, the <span class="hlt">electronic</span> <span class="hlt">transport</span> and reliability of these materials are important to study and understand. We report on a charge <span class="hlt">transport</span> model to predict leakage current and failure trends based on previously published data for a stoichiometric silicon nitride dielectric. Failure occurs when the defect density increases to a critical value of approximately 6 × 1025 traps/m3. The model's parameters are determined using voltage ramp data only, and yet, the model is also able to predict constant voltage stress failure over a time scale ranging from minutes to months. The successful fit of the model to the experimental data validates our assumption that the dominant defect in the dielectric is the Si dangling bond, located approximately 2.2 eV below the conduction band. A comparison with previous SiCOH simulations shows SiN and SiCOH have similar defect-related material properties. It is also speculated that, based on the estimated parameter values of 2.75 eV for the defect formation activation energy, the materials' TDDB wear-out are caused by broken Si-H bonds, resulting in Si dangling bond defects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhDT........59G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhDT........59G"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">environments</span> and electrochemical properties in lithium storage materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Graetz, Jason Allan</p> <p></p> <p>One of the large controversies regarding lithium cathodes concerns the arrangement of the local <span class="hlt">electronic</span> <span class="hlt">environments</span> in the host material and how these <span class="hlt">environments</span> are affected by lithium intercalation. <span class="hlt">Electron</span> energy-loss spectrometry was used to study charge compensation in lithiated transition-metal oxides (e.g., LiCoO2 and LiNi0.8Co0.2O 2) during electrochemical cycling. The oxygen K-edge and transition metal L2,3 white lines were used to probe the oxygen 2p and transition metal 3d states, respectively. These results show a large increase in state occupancy of the oxygen 2p band during lithiation, suggesting that much of the lithium 2s <span class="hlt">electron</span> is accommodated by the anion. Ab initio calculations of the oxygen 2p partial density of states curves confirm the increase in unoccupied states that accompany lithium extraction. In contrast with the large changes observed in the oxygen K-edge, much smaller changes were observed in the transition metal L2,3 white lines. Surprisingly, for layered LiCoO 2 and Li(Ni, Co)O2, the transition metal valence changes little during the charge compensation accompanying lithiation. Recent demand for alternatives to graphitic carbon for lithium anodes motivated an investigation into novel binary lithium alloys. The large volume expansions associated with lithium insertion is known to generate tremendous microstructural damage, making most alloys unsuitable for rechargeable lithium batteries. Electrodes of nanostructured lithium alloys were prepared in an attempt to mitigate the particle decrepitation that occurs during cycling and to shorten diffusion times for lithium. Anodes of silicon and germanium were prepared in thin film form as nanocrystalline particles (10 nm mean diameter) and as continuous amorphous thin films (60--250 nm thick). These nanostructured materials exhibited stable capacities up to six times larger than what is found in graphitic carbons, which are currently the industry standard. In addition, these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15305511','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15305511"><span id="translatedtitle">Survey of <span class="hlt">transport</span> <span class="hlt">environments</span> of circus tigers (Panthera tigris).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nevill, Christian H; Friend, Ted H; Toscano, Michael J</p> <p>2004-06-01</p> <p>The type of equipment used to <span class="hlt">transport</span> circus tigers, environmental factors experienced during <span class="hlt">transport</span>, and resultant body temperatures of tigers <span class="hlt">transported</span> were surveyed during hot and cold weather conditions with six different circus tiger acts. Dataloggers recorded interior and exterior temperatures, relative humidity, and radiant heat at 5-min intervals during each trip. Microdataloggers fed to the tigers recorded body temperature and were recovered from eight Bengal (Panthera tigris tigris), Siberian (P. t. altaica), or Bengal-Sumatran (P. t. tigris-P. t. sumatrae) cross tigers from four different circuses. Three basic types of systems were used by circus acts to <span class="hlt">transport</span> tigers: freestanding cages mounted on wheels that were winched or pushed into a semitrailer for <span class="hlt">transport</span>, cages built into the trailer itself, and weather-resistant units <span class="hlt">transported</span> on flatbed railcars or flatbed truck trailers. The highest temperature encountered inside a trailer was 37.3 degrees C in hot weather conditions, but overall, temperatures were usually between 21.1-26.7 degrees C. Temperature inside the trailers did not appear to be affected by movement and did not generally exceed ambient temperatures, indicating adequate insulation and passive ventilation. During cold weather trips, the lowest temperature inside the trailers was -1.1 degrees C, occurring during an overnight stop. Interior temperatures during cold weather <span class="hlt">transport</span> stayed 2-6 degrees C warmer than ambient temperatures. The body temperatures of the tigers were unaffected by extreme temperatures. The only changes observed in body temperature were increases of 1-2 degrees C caused by activity and excitement associated with loading in several groups of tigers, regardless of whether it was hot or cold weather. Whenever measured, carbon monoxide and ammonia were below the detectable concentrations of 10 and 1 ppm. respectively. Overall, <span class="hlt">transport</span> did not appear to have any adverse effects on the tigers' ability</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15305511','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15305511"><span id="translatedtitle">Survey of <span class="hlt">transport</span> <span class="hlt">environments</span> of circus tigers (Panthera tigris).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nevill, Christian H; Friend, Ted H; Toscano, Michael J</p> <p>2004-06-01</p> <p>The type of equipment used to <span class="hlt">transport</span> circus tigers, environmental factors experienced during <span class="hlt">transport</span>, and resultant body temperatures of tigers <span class="hlt">transported</span> were surveyed during hot and cold weather conditions with six different circus tiger acts. Dataloggers recorded interior and exterior temperatures, relative humidity, and radiant heat at 5-min intervals during each trip. Microdataloggers fed to the tigers recorded body temperature and were recovered from eight Bengal (Panthera tigris tigris), Siberian (P. t. altaica), or Bengal-Sumatran (P. t. tigris-P. t. sumatrae) cross tigers from four different circuses. Three basic types of systems were used by circus acts to <span class="hlt">transport</span> tigers: freestanding cages mounted on wheels that were winched or pushed into a semitrailer for <span class="hlt">transport</span>, cages built into the trailer itself, and weather-resistant units <span class="hlt">transported</span> on flatbed railcars or flatbed truck trailers. The highest temperature encountered inside a trailer was 37.3 degrees C in hot weather conditions, but overall, temperatures were usually between 21.1-26.7 degrees C. Temperature inside the trailers did not appear to be affected by movement and did not generally exceed ambient temperatures, indicating adequate insulation and passive ventilation. During cold weather trips, the lowest temperature inside the trailers was -1.1 degrees C, occurring during an overnight stop. Interior temperatures during cold weather <span class="hlt">transport</span> stayed 2-6 degrees C warmer than ambient temperatures. The body temperatures of the tigers were unaffected by extreme temperatures. The only changes observed in body temperature were increases of 1-2 degrees C caused by activity and excitement associated with loading in several groups of tigers, regardless of whether it was hot or cold weather. Whenever measured, carbon monoxide and ammonia were below the detectable concentrations of 10 and 1 ppm. respectively. Overall, <span class="hlt">transport</span> did not appear to have any adverse effects on the tigers' ability</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JAP....83.3207B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JAP....83.3207B"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> across metal/discotic liquid crystal interfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boden, N.; Bushby, R. J.; Clements, J.; Movaghar, B.</p> <p>1998-03-01</p> <p><span class="hlt">Electron</span> <span class="hlt">transport</span> across micron thick films of columnar hexagonal discotic liquid crystal phases homeotropically aligned between metal electrode surfaces has been studied both experimentally and theoretically. These molecules are unique in their combination of charge <span class="hlt">transport</span> along individual molecular columns with liquidlike self-organization. Typical of organic insulators, a high resistance Ohmic regime is evident at fields of less than 0.05 MV cm-1, due to a low concentration of chemical impurities (n<109cm-3), and a space-charge injection regime at higher fields. Breakdown fields are reasonably high: in hexakis(hexyloxy)triphenylene they reach ˜5 MV cm-1 at room temperature. Our results show that triphenylene-based discotics form an excellent class of highly ordered optically transparent insulators. At high temperatures and high fields the current is injection controlled and exhibits typical tunneling and space charge limited, nonlinear I-V characteristics. Dramatic jumps in injection currents are observed at phase transitions. The change at the crystalline to liquid crystalline phase transition is mainly due to more efficient "wetting" of the electrode surface in the liquid crystalline phase, whilst at the liquid crystalline to isotropic phase transition it arises from the enhancement in the molecular mobility. The concepts of semiconducting gaps, band mobilities, and carrier injection rates are extended to these new materials. The experimental observations are interpreted in a framework which takes into account the important role played by liquidlike dynamics in establishing the microscopic structural order in, what is, otherwise a highly anisotropic and weakly bonded "molecular crystal."</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26575923','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26575923"><span id="translatedtitle"><span class="hlt">Electronic</span> Energy Transfer in Polarizable Heterogeneous <span class="hlt">Environments</span>: A Systematic Investigation of Different Quantum Chemical Approaches.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Steinmann, Casper; Kongsted, Jacob</p> <p>2015-09-01</p> <p>Theoretical prediction of <span class="hlt">transport</span> and optical properties of protein-pigment complexes is of significant importance when aiming at understanding the structure-function relationship in such systems. <span class="hlt">Electronic</span> energy transfer (EET) couplings represent a key property in this respect since such couplings provide important insight into the strength of interaction between photoactive pigments in protein-pigment complexes. Recently, attention has been payed to how the <span class="hlt">environment</span> modifies or even controls the <span class="hlt">electronic</span> couplings. To enable such theoretical predictions, a fully polarizable embedding model has been suggested (Curutchet, C., et al. J. Chem. Theory Comput., 2009, 5, 1838-1848). In this work, we further develop this computational model by extending it with an ab initio derived polarizable force field including higher-order multipole moments. We use this extended model to systematically examine three different ways of obtaining EET couplings in a heterogeneous medium ranging from use of the exact transition density to a point-dipole approximation. Several interesting observations are made, for example, the explicit use of transition densities in the calculation of the <span class="hlt">electronic</span> couplings, and also when including the explicit <span class="hlt">environment</span> contribution, can be replaced by a much simpler transition point charge description without comprising the quality of the model predictions. PMID:26575923</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26575923','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26575923"><span id="translatedtitle"><span class="hlt">Electronic</span> Energy Transfer in Polarizable Heterogeneous <span class="hlt">Environments</span>: A Systematic Investigation of Different Quantum Chemical Approaches.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Steinmann, Casper; Kongsted, Jacob</p> <p>2015-09-01</p> <p>Theoretical prediction of <span class="hlt">transport</span> and optical properties of protein-pigment complexes is of significant importance when aiming at understanding the structure-function relationship in such systems. <span class="hlt">Electronic</span> energy transfer (EET) couplings represent a key property in this respect since such couplings provide important insight into the strength of interaction between photoactive pigments in protein-pigment complexes. Recently, attention has been payed to how the <span class="hlt">environment</span> modifies or even controls the <span class="hlt">electronic</span> couplings. To enable such theoretical predictions, a fully polarizable embedding model has been suggested (Curutchet, C., et al. J. Chem. Theory Comput., 2009, 5, 1838-1848). In this work, we further develop this computational model by extending it with an ab initio derived polarizable force field including higher-order multipole moments. We use this extended model to systematically examine three different ways of obtaining EET couplings in a heterogeneous medium ranging from use of the exact transition density to a point-dipole approximation. Several interesting observations are made, for example, the explicit use of transition densities in the calculation of the <span class="hlt">electronic</span> couplings, and also when including the explicit <span class="hlt">environment</span> contribution, can be replaced by a much simpler transition point charge description without comprising the quality of the model predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PhDT........72B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhDT........72B"><span id="translatedtitle">Nonlinear quantum <span class="hlt">transport</span> in low-dimensional <span class="hlt">electronic</span> devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barrios, Andres Javier</p> <p></p> <p>The study of <span class="hlt">transport</span> processes in low-dimensional semiconductors requires a rigorous quantum mechanical treatment. However, a full-fledged quantum <span class="hlt">transport</span> theory of <span class="hlt">electrons</span> (or holes) in semiconductors of small scale, applicable in the presence of external fields of arbitrary strength, is still not available. In the literature, different approaches have been proposed, including: (a) the semiclassical Boltzmann equation, (b) perturbation theory based on Keldysh's Green functions, and (c) the Quantum Boltzmann Equation (QBE), previously derived by Van Vliet and coworkers, applicable in the realm of Kubo's Linear Response Theory (LRT). In the present work, we follow the method originally proposed by Van Wet in LRT. The Hamiltonian in this approach is of the form: H = H 0(E, B) + lambdaV, where H0 contains the externally applied fields, and lambdaV includes many-body interactions. This Hamiltonian differs from the LRT Hamiltonian, H = H0 - AF(t) + lambdaV, which contains the external field in the field-response part, -AF(t). For the nonlinear problem, the eigenfunctions of the system Hamiltonian, H0(E, B), include the external fields without any limitation on strength. In Part A of this dissertation, both the diagonal and nondiagonal Master equations are obtained after applying projection operators to the von Neumann equation for the density operator in the interaction picture, and taking the Van Hove limit, (lambda → 0, t → infinity, so that (lambda2 t)n remains finite). Similarly, the many-body current operator J is obtained from the Heisenberg equation of motion. In Part B, the Quantum Boltzmann Equation is obtained in the occupation-number representation for an <span class="hlt">electron</span> gas, interacting with phonons or impurities. On the one-body level, the current operator obtained in Part A leads to the Generalized Calecki current for electric and magnetic fields of arbitrary strength. Furthermore, in this part, the LRT results for the current and conductance are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050169213','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050169213"><span id="translatedtitle">Energetic <span class="hlt">Electron</span> <span class="hlt">Transport</span> in the Inner Magnetosphere During Geomagnetic Storms and Substorms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McKenzie, D. L.; Anderson, P. C.</p> <p>2005-01-01</p> <p>We propose to examine the relationship of geomagnetic storms and substorms and the <span class="hlt">transport</span> of energetic particles in the inner magnetosphere using measurements of the auroral X-ray emissions by PIXIE. PIXIE provides a global view of the auroral oval for the extended periods of time required to study stormtime phenomena. Its unique energy response and global view allow separation of stormtime particle <span class="hlt">transport</span> driven by strong magnetospheric electric fields from substorm particle <span class="hlt">transport</span> driven by magnetic-field dipolarization and subsequent particle injection. The relative importance of substorms in releasing stored magnetospheric energy during storms and injecting particles into the inner magnetosphere and the ring current is currently hotly debated. The distribution of particles in the inner magnetosphere is often inferred from measurements of the precipitating auroral particles. Thus, the global distributions of the characteristics of energetic precipitating particles during storms and substorms are extremely important inputs to any description or model of the geospace <span class="hlt">environment</span> and the Sun-Earth connection. We propose to use PIXIE observations and modeling of the <span class="hlt">transport</span> of energetic <span class="hlt">electrons</span> to examine the relationship between storms and substorms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPS...320..343H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPS...320..343H"><span id="translatedtitle">Quantification of ionic <span class="hlt">transport</span> within thermally-activated batteries using <span class="hlt">electron</span> probe micro-analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Humplik, Thomas; Stirrup, Emily K.; Grillet, Anne M.; Grant, Richard P.; Allen, Ashley N.; Wesolowski, Daniel E.; Roberts, Christine C.</p> <p>2016-07-01</p> <p>The transient <span class="hlt">transport</span> of electrolytes in thermally-activated batteries is studied using <span class="hlt">electron</span> probe micro-analysis (EPMA), demonstrating the robust capability of EPMA as a useful tool for studying and quantifying mass <span class="hlt">transport</span> within porous materials, particularly in difficult <span class="hlt">environments</span> where classical flow measurements are challenging. By tracking the mobility of bromine and potassium ions from the electrolyte stored within the separator into the lithium silicon anode and iron disulfide cathode, we are able to quantify the <span class="hlt">transport</span> mechanisms and physical properties of the electrodes including permeability and tortuosity. Due to the micron to submicron scale porous structure of the initially dry anode, a fast capillary pressure driven flow is observed into the anode from which we are able to set a lower bound on the permeability of 10-1 mDarcy. The <span class="hlt">transport</span> into the cathode is diffusion-limited because the cathode originally contained some electrolyte before activation. Using a transient one-dimensional diffusion model, we estimate the tortuosity of the cathode electrode to be 2.8 ± 0.8.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Nanot..27H5503P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Nanot..27H5503P&link_type=ABSTRACT"><span id="translatedtitle">Surface trap mediated <span class="hlt">electronic</span> <span class="hlt">transport</span> in biofunctionalized silicon nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Puppo, F.; Traversa, F. L.; Di Ventra, M.; De Micheli, G.; Carrara, S.</p> <p>2016-08-01</p> <p>Silicon nanowires (SiNWs), fabricated via a top-down approach and then functionalized with biological probes, are used for electrically-based sensing of breast tumor markers. The SiNWs, featuring memristive-like behavior in bare conditions, show, in the presence of biomarkers, modified hysteresis and, more importantly, a voltage memory component, namely a voltage gap. The voltage gap is demonstrated to be a novel and powerful parameter of detection thanks to its high-resolution dependence on charges in proximity of the wire. This unique approach of sensing has never been studied and adopted before. Here, we propose a physical model of the surface <span class="hlt">electronic</span> <span class="hlt">transport</span> in Schottky barrier SiNW biosensors, aiming at reproducing and understanding the voltage gap based behavior. The implemented model describes well the experimental I–V characteristics of the device. It also links the modification of the voltage gap to the changing concentration of antigens by showing the decrease of this parameter in response to increasing concentrations of the molecules that are detected with femtomolar resolution in real human samples. Both experiments and simulations highlight the predominant role of the dynamic recombination of the nanowire surface states, with the incoming external charges from bio-species, in the appearance and modification of the voltage gap. Finally, thanks to its compactness, and strict correlation with the physics of the nanodevice, this model can be used to describe and predict the I–V characteristics in other nanostructured devices, for different than antibody-based sensing as well as <span class="hlt">electronic</span> applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27418560','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27418560"><span id="translatedtitle">Surface trap mediated <span class="hlt">electronic</span> <span class="hlt">transport</span> in biofunctionalized silicon nanowires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Puppo, F; Traversa, F L; Ventra, M Di; Micheli, G De; Carrara, S</p> <p>2016-08-26</p> <p>Silicon nanowires (SiNWs), fabricated via a top-down approach and then functionalized with biological probes, are used for electrically-based sensing of breast tumor markers. The SiNWs, featuring memristive-like behavior in bare conditions, show, in the presence of biomarkers, modified hysteresis and, more importantly, a voltage memory component, namely a voltage gap. The voltage gap is demonstrated to be a novel and powerful parameter of detection thanks to its high-resolution dependence on charges in proximity of the wire. This unique approach of sensing has never been studied and adopted before. Here, we propose a physical model of the surface <span class="hlt">electronic</span> <span class="hlt">transport</span> in Schottky barrier SiNW biosensors, aiming at reproducing and understanding the voltage gap based behavior. The implemented model describes well the experimental I-V characteristics of the device. It also links the modification of the voltage gap to the changing concentration of antigens by showing the decrease of this parameter in response to increasing concentrations of the molecules that are detected with femtomolar resolution in real human samples. Both experiments and simulations highlight the predominant role of the dynamic recombination of the nanowire surface states, with the incoming external charges from bio-species, in the appearance and modification of the voltage gap. Finally, thanks to its compactness, and strict correlation with the physics of the nanodevice, this model can be used to describe and predict the I-V characteristics in other nanostructured devices, for different than antibody-based sensing as well as <span class="hlt">electronic</span> applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Nanot..27H5503P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nanot..27H5503P"><span id="translatedtitle">Surface trap mediated <span class="hlt">electronic</span> <span class="hlt">transport</span> in biofunctionalized silicon nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Puppo, F.; Traversa, F. L.; Di Ventra, M.; De Micheli, G.; Carrara, S.</p> <p>2016-08-01</p> <p>Silicon nanowires (SiNWs), fabricated via a top-down approach and then functionalized with biological probes, are used for electrically-based sensing of breast tumor markers. The SiNWs, featuring memristive-like behavior in bare conditions, show, in the presence of biomarkers, modified hysteresis and, more importantly, a voltage memory component, namely a voltage gap. The voltage gap is demonstrated to be a novel and powerful parameter of detection thanks to its high-resolution dependence on charges in proximity of the wire. This unique approach of sensing has never been studied and adopted before. Here, we propose a physical model of the surface <span class="hlt">electronic</span> <span class="hlt">transport</span> in Schottky barrier SiNW biosensors, aiming at reproducing and understanding the voltage gap based behavior. The implemented model describes well the experimental I-V characteristics of the device. It also links the modification of the voltage gap to the changing concentration of antigens by showing the decrease of this parameter in response to increasing concentrations of the molecules that are detected with femtomolar resolution in real human samples. Both experiments and simulations highlight the predominant role of the dynamic recombination of the nanowire surface states, with the incoming external charges from bio-species, in the appearance and modification of the voltage gap. Finally, thanks to its compactness, and strict correlation with the physics of the nanodevice, this model can be used to describe and predict the I-V characteristics in other nanostructured devices, for different than antibody-based sensing as well as <span class="hlt">electronic</span> applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22341856','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22341856"><span id="translatedtitle">Study of <span class="hlt">electronic</span> <span class="hlt">transport</span> in gamma ray exposed nanowires</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gehlawat, Devender Chauhan, R.P.</p> <p>2014-01-01</p> <p>Graphical abstract: A sharp decline in the I–V characteristics of Cu (and Cd) nanowires was experimentally observed after the gamma ray exposure of nanowires. Irradiation induced transformations in the granular properties and the resonance state of electron–phonon coupling beyond a particular value of external field may be accountable for observed shape of I–V characteristics in gamma ray exposed nanowires. - Highlights: • Cu and Cd nanowires were synthesized by technique of electrodeposition in templates. • The nanowires were exposed to different doses of gamma ray photons. • A sharp decline in the current in I–V characteristics (IVC) was observed. • Structural deviation in terms of granular orientations was also analysed. • The electron–phonon coupling may be responsible for observed sharp decline in IVC. - Abstract: One dimensional nanostructures provide the most restricted and narrow channel for the <span class="hlt">transport</span> of charge carriers and therefore 1D structures preserve their significance from the viewpoint of <span class="hlt">electronic</span> devices. The net radiation effect on nanomaterials is expected to be more (due to their increased reactivity and lesser bulk volume) than their bulk counterparts. Radiation often modifies the structure and simultaneously the other physical properties of materials. In this manner, the irradiation phenomenon could be counted as a strong criterion to induce changes in the structural and electrical properties of nanowires. We have studied the effect of gamma rays on the <span class="hlt">electronic</span> flow through Cu and Cd nanowires by plotting their I–V characteristics (IVC). The IVC of gamma ray exposed nanowires was found to be a combination of the linear and nonlinear regions and a decreasing pattern in the electrical conductivity (calculated from the linear portion of IVC) was observed as we increased the dose of gamma rays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27418560','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27418560"><span id="translatedtitle">Surface trap mediated <span class="hlt">electronic</span> <span class="hlt">transport</span> in biofunctionalized silicon nanowires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Puppo, F; Traversa, F L; Ventra, M Di; Micheli, G De; Carrara, S</p> <p>2016-08-26</p> <p>Silicon nanowires (SiNWs), fabricated via a top-down approach and then functionalized with biological probes, are used for electrically-based sensing of breast tumor markers. The SiNWs, featuring memristive-like behavior in bare conditions, show, in the presence of biomarkers, modified hysteresis and, more importantly, a voltage memory component, namely a voltage gap. The voltage gap is demonstrated to be a novel and powerful parameter of detection thanks to its high-resolution dependence on charges in proximity of the wire. This unique approach of sensing has never been studied and adopted before. Here, we propose a physical model of the surface <span class="hlt">electronic</span> <span class="hlt">transport</span> in Schottky barrier SiNW biosensors, aiming at reproducing and understanding the voltage gap based behavior. The implemented model describes well the experimental I-V characteristics of the device. It also links the modification of the voltage gap to the changing concentration of antigens by showing the decrease of this parameter in response to increasing concentrations of the molecules that are detected with femtomolar resolution in real human samples. Both experiments and simulations highlight the predominant role of the dynamic recombination of the nanowire surface states, with the incoming external charges from bio-species, in the appearance and modification of the voltage gap. Finally, thanks to its compactness, and strict correlation with the physics of the nanodevice, this model can be used to describe and predict the I-V characteristics in other nanostructured devices, for different than antibody-based sensing as well as <span class="hlt">electronic</span> applications. PMID:27418560</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26658001','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26658001"><span id="translatedtitle">Vibrio Iron <span class="hlt">Transport</span>: Evolutionary Adaptation to Life in Multiple <span class="hlt">Environments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Payne, Shelley M; Mey, Alexandra R; Wyckoff, Elizabeth E</p> <p>2016-03-01</p> <p>Iron is an essential element for Vibrio spp., but the acquisition of iron is complicated by its tendency to form insoluble ferric complexes in nature and its association with high-affinity iron-binding proteins in the host. Vibrios occupy a variety of different niches, and each of these niches presents particular challenges for acquiring sufficient iron. Vibrio species have evolved a wide array of iron <span class="hlt">transport</span> systems that allow the bacteria to compete for this essential element in each of its habitats. These systems include the secretion and uptake of high-affinity iron-binding compounds (siderophores) as well as <span class="hlt">transport</span> systems for iron bound to host complexes. <span class="hlt">Transporters</span> for ferric and ferrous iron not complexed to siderophores are also common to Vibrio species. Some of the genes encoding these systems show evidence of horizontal transmission, and the ability to acquire and incorporate additional iron <span class="hlt">transport</span> systems may have allowed Vibrio species to more rapidly adapt to new environmental niches. While too little iron prevents growth of the bacteria, too much can be lethal. The appropriate balance is maintained in vibrios through complex regulatory networks involving transcriptional repressors and activators and small RNAs (sRNAs) that act posttranscriptionally. Examination of the number and variety of iron <span class="hlt">transport</span> systems found in Vibrio spp. offers insights into how this group of bacteria has adapted to such a wide range of habitats.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3529018','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3529018"><span id="translatedtitle">Motor <span class="hlt">transport</span> of self-assembled cargos in crowded <span class="hlt">environments</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Conway, Leslie; Wood, Derek; Tüzel, Erkan; Ross, Jennifer L.</p> <p>2012-01-01</p> <p>Intracellular <span class="hlt">transport</span> of cargo particles is performed by multiple motors working in concert. However, the mechanism of motor association to cargos is unknown. It is also unknown how long individual motors stay attached, how many are active, and how multimotor cargos would navigate a densely crowded filament with many other motors. Prior theoretical and experimental biophysical model systems of intracellular cargo have assumed fixed teams of motors <span class="hlt">transporting</span> along bare microtubules or microtubules with fixed obstacles. Here, we investigate a regime of cargos <span class="hlt">transporting</span> along microtubules crowded with free motors. Furthermore, we use cargos that are able to associate or dissociate motors as it translocates. We perform in vitro motility reconstitution experiments with high-resolution particle tracking. Our model system consists of a quantum dot cargo attached to kinesin motors, and additional free kinesin motors that act as traffic along the microtubule. Although high densities of kinesin motors hinder forward motion, resulting in a lower velocity, the ability to associate motors appears to enhance the run length and attachment time of the quantum dot, improving overall cargo <span class="hlt">transport</span>. These results suggest that cargos that can associate new motors as they <span class="hlt">transport</span> could overcome traffic jams. PMID:23213204</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1185679-defect-mediated-transport-electronic-irradiation-effect-individual-domains-cvd-grown-monolayer-mos2','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1185679-defect-mediated-transport-electronic-irradiation-effect-individual-domains-cvd-grown-monolayer-mos2"><span id="translatedtitle">Defect-mediated <span class="hlt">transport</span> and <span class="hlt">electronic</span> irradiation effect in individual domains of CVD-grown monolayer MoS2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Durand, Corentin; Zhang, Xiaoguang; Fowlkes, Jason; Najmaei, Sina; Lou, Jun; Li, An -Ping</p> <p>2015-01-16</p> <p>We study the electrical <span class="hlt">transport</span> properties of atomically thin individual crystalline grains of MoS2 with four-probe scanning tunneling microscopy. The monolayer MoS2 domains are synthesized by chemical vapor deposition on SiO2/Si substrate. Temperature dependent measurements on conductance and mobility show that <span class="hlt">transport</span> is dominated by an <span class="hlt">electron</span> charge trapping and thermal release process with very low carrier density and mobility. The effects of <span class="hlt">electronic</span> irradiation are examined by exposing the film to <span class="hlt">electron</span> beam in the scanning <span class="hlt">electron</span> microscope in an ultrahigh vacuum <span class="hlt">environment</span>. The irradiation process is found to significantly affect the mobility and the carrier density of themore » material, with the conductance showing a peculiar time-dependent relaxation behavior. It is suggested that the presence of defects in active MoS2 layer and dielectric layer create charge trapping sites, and a multiple trapping and thermal release process dictates the <span class="hlt">transport</span> and mobility characteristics. The <span class="hlt">electron</span> beam irradiation promotes the formation of defects and impact the electrical properties of MoS2. Finally, our study reveals the important roles of defects and the <span class="hlt">electron</span> beam irradiation effects in the <span class="hlt">electronic</span> properties of atomic layers of MoS2.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...627049F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...627049F"><span id="translatedtitle">Defect engineering of the <span class="hlt">electronic</span> <span class="hlt">transport</span> through cuprous oxide interlayers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fadlallah, Mohamed M.; Eckern, Ulrich; Schwingenschlögl, Udo</p> <p>2016-06-01</p> <p>The <span class="hlt">electronic</span> <span class="hlt">transport</span> through Au–(Cu2O)n–Au junctions is investigated using first-principles calculations and the nonequilibrium Green’s function method. The effect of varying the thickness (i.e., n) is studied as well as that of point defects and anion substitution. For all Cu2O thicknesses the conductance is more enhanced by bulk-like (in contrast to near-interface) defects, with the exception of O vacancies and Cl substitutional defects. A similar transmission behavior results from Cu deficiency and N substitution, as well as from Cl substitution and N interstitials for thick Cu2O junctions. In agreement with recent experimental observations, it is found that N and Cl doping enhances the conductance. A Frenkel defect, i.e., a superposition of an O interstitial and O substitutional defect, leads to a remarkably high conductance. From the analysis of the defect formation energies, Cu vacancies are found to be particularly stable, in agreement with earlier experimental and theoretical work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6067021','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6067021"><span id="translatedtitle">Considerations of beta and <span class="hlt">electron</span> <span class="hlt">transport</span> in internal dose calculations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bolch, W.E.; Poston, J.W. Sr. . Dept. of Nuclear Engineering)</p> <p>1990-12-01</p> <p>Ionizing radiation has broad uses in modern science and medicine. These uses often require the calculation of energy deposition in the irradiated media and, usually, the medium of interest is the human body. Energy deposition from radioactive sources within the human body and the effects of such deposition are considered in the field of internal dosimetry. In July of 1988, a three-year research project was initiated by the Nuclear Engineering Department at Texas A M University under the sponsorship of the US Department of Energy. The main thrust of the research was to consider, for the first time, the detailed spatial <span class="hlt">transport</span> of <span class="hlt">electron</span> and beta particles in the estimation of average organ doses under the Medical Internal Radiation Dose (MIRD) schema. At the present time (December of 1990), research activities are continuing within five areas. Several are new initiatives begun within the second or third year of the current contract period. They include: (1) development of small-scale dosimetry; (2) development of a differential volume phantom; (3) development of a dosimetric bone model; (4) assessment of the new ICRP lung model; and (5) studies into the mechanisms of DNA damage. A progress report is given for each of these tasks within the Comprehensive Report. In each use, preliminary results are very encouraging and plans for further research are detailed within this document. 22 refs., 13 figs., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4891735','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4891735"><span id="translatedtitle">Defect engineering of the <span class="hlt">electronic</span> <span class="hlt">transport</span> through cuprous oxide interlayers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fadlallah, Mohamed M.; Eckern, Ulrich; Schwingenschlögl, Udo</p> <p>2016-01-01</p> <p>The <span class="hlt">electronic</span> <span class="hlt">transport</span> through Au–(Cu2O)n–Au junctions is investigated using first-principles calculations and the nonequilibrium Green’s function method. The effect of varying the thickness (i.e., n) is studied as well as that of point defects and anion substitution. For all Cu2O thicknesses the conductance is more enhanced by bulk-like (in contrast to near-interface) defects, with the exception of O vacancies and Cl substitutional defects. A similar transmission behavior results from Cu deficiency and N substitution, as well as from Cl substitution and N interstitials for thick Cu2O junctions. In agreement with recent experimental observations, it is found that N and Cl doping enhances the conductance. A Frenkel defect, i.e., a superposition of an O interstitial and O substitutional defect, leads to a remarkably high conductance. From the analysis of the defect formation energies, Cu vacancies are found to be particularly stable, in agreement with earlier experimental and theoretical work. PMID:27256905</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1200859-electronic-transport-two-dimensional-high-dielectric-constant-nanosystems','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1200859-electronic-transport-two-dimensional-high-dielectric-constant-nanosystems"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> in two-dimensional high dielectric constant nanosystems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Ortuño, M.; Somoza, A. M.; Vinokur, V. M.; Baturina, T. I.</p> <p>2015-04-10</p> <p>There has been remarkable recent progress in engineering high-dielectric constant two dimensional (2D) materials, which are being actively pursued for applications in nanoelectronics in capacitor and memory devices, energy storage, and high-frequency modulation in communication devices. Yet many of the unique properties of these systems are poorly understood and remain unexplored. Here we report a numerical study of hopping conductivity of the lateral network of capacitors, which models two-dimensional insulators, and demonstrate that 2D long-range Coulomb interactions lead to peculiar size effects. We find that the characteristic energy governing <span class="hlt">electronic</span> <span class="hlt">transport</span> scales logarithmically with either system size or electrostatic screeningmore » length depending on which one is shorter. Our results are relevant well beyond their immediate context, explaining, for example, recent experimental observations of logarithmic size dependence of electric conductivity of thin superconducting films in the critical vicinity of superconductor-insulator transition where a giant dielectric constant develops. Our findings mark a radical departure from the orthodox view of conductivity in 2D systems as a local characteristic of materials and establish its macroscopic global character as a generic property of high-dielectric constant 2D nanomaterials.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PhDT........42Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PhDT........42Y"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> of N-type semiconductor nanocrystalline solids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Dong</p> <p>2005-07-01</p> <p>A bottleneck limiting the widespread applications of semiconductor nanocrystalline solids on optoelectronic devices such as photovoltaic cells, light emitting devices and quantum dots lasers is their poor conductivity. In this thesis, we show that the conductivity of thin films of CdSe nanocrystals is increased by many orders of magnitude when n-doped either by potassium or electrochemistry. Around half-filling of the first <span class="hlt">electronic</span> shell, a peak in the conductivity is observed indicating shell to shell <span class="hlt">transport</span>. Introducing conjugated ligands between nanocrystals increases the conductivities to ˜10-2 S cm. NaOH treatment of the thin films leads to a large carrier mobility and a semiconductor nanocrystals field effect transistor is produced. The temperature and electrical field dependent conductivity of n-type CdSe nanocrystal thin films is then investigated. The low field conductivity follows exp(-(T*/T)-1/2 ) and high field conductivity follows exp(-(E*/ E)-1/2). The complete behavior is very well described by the variable range hopping theory with a Coulomb gap. Finally, n-type colloidal CdSe nanocrystalline solids show large positive magnetoresistance at low temperatures (0.3K--4K). We attempted to dope Manganese (II) ions in nanocrystals, which might show interesting negative magnetoresistance. However, they still show similar positive magnetoresistance probably due to the difficulty of Mn doping. At ˜0.3K the resistance is increased by ˜150% at 10 Tesla.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6067078','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6067078"><span id="translatedtitle">Considerations of beta and <span class="hlt">electron</span> <span class="hlt">transport</span> in internal dose calculations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bolch, W.E.; Poston, J.W. Sr.</p> <p>1990-12-01</p> <p>Ionizing radiation has broad uses in modern science and medicine. These uses often require the calculation of energy deposition in the irradiated media and, usually, the medium of interest is the human body. Energy deposition from radioactive sources within the human body and the effects of such deposition are considered in the field of internal dosimetry. In July of 1988, a three-year research project was initiated by the Nuclear Engineering Department at Texas A M University under the sponsorship of the US Department of Energy. The main thrust of the research was to consider, for the first time, the detailed spatial <span class="hlt">transport</span> of <span class="hlt">electron</span> and beta particles in the estimation of average organ doses under the Medical Internal Radiation Dose (MIRD) schema. At the present time (December of 1990), research activities are continuing within five areas. Several are new initiatives begun within the second or third year of the current contract period. They include: (1) development of small-scale dosimetry; (2) development of a differential volume phantom; (3) development of a dosimetric bone model; (4) assessment of the new ICRP lung model; and (5) studies into the mechanisms of DNA damage. A progress report is given for each of these tasks within the Comprehensive Report. In each case, preliminary results are very encouraging and plans for further research are detailed within this document.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatSR...5E9667O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatSR...5E9667O"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> in two-dimensional high dielectric constant nanosystems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ortuño, M.; Somoza, A. M.; Vinokur, V. M.; Baturina, T. I.</p> <p>2015-04-01</p> <p>There has been remarkable recent progress in engineering high-dielectric constant two dimensional (2D) materials, which are being actively pursued for applications in nanoelectronics in capacitor and memory devices, energy storage, and high-frequency modulation in communication devices. Yet many of the unique properties of these systems are poorly understood and remain unexplored. Here we report a numerical study of hopping conductivity of the lateral network of capacitors, which models two-dimensional insulators, and demonstrate that 2D long-range Coulomb interactions lead to peculiar size effects. We find that the characteristic energy governing <span class="hlt">electronic</span> <span class="hlt">transport</span> scales logarithmically with either system size or electrostatic screening length depending on which one is shorter. Our results are relevant well beyond their immediate context, explaining, for example, recent experimental observations of logarithmic size dependence of electric conductivity of thin superconducting films in the critical vicinity of superconductor-insulator transition where a giant dielectric constant develops. Our findings mark a radical departure from the orthodox view of conductivity in 2D systems as a local characteristic of materials and establish its macroscopic global character as a generic property of high-dielectric constant 2D nanomaterials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1200859','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1200859"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> in two-dimensional high dielectric constant nanosystems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ortuño, M.; Somoza, A. M.; Vinokur, V. M.; Baturina, T. I.</p> <p>2015-04-10</p> <p>There has been remarkable recent progress in engineering high-dielectric constant two dimensional (2D) materials, which are being actively pursued for applications in nanoelectronics in capacitor and memory devices, energy storage, and high-frequency modulation in communication devices. Yet many of the unique properties of these systems are poorly understood and remain unexplored. Here we report a numerical study of hopping conductivity of the lateral network of capacitors, which models two-dimensional insulators, and demonstrate that 2D long-range Coulomb interactions lead to peculiar size effects. We find that the characteristic energy governing <span class="hlt">electronic</span> <span class="hlt">transport</span> scales logarithmically with either system size or electrostatic screening length depending on which one is shorter. Our results are relevant well beyond their immediate context, explaining, for example, recent experimental observations of logarithmic size dependence of electric conductivity of thin superconducting films in the critical vicinity of superconductor-insulator transition where a giant dielectric constant develops. Our findings mark a radical departure from the orthodox view of conductivity in 2D systems as a local characteristic of materials and establish its macroscopic global character as a generic property of high-dielectric constant 2D nanomaterials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990071231','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990071231"><span id="translatedtitle">Inner Magnetospheric Superthermal <span class="hlt">Electron</span> <span class="hlt">Transport</span>: Photoelectron and Plasma Sheet <span class="hlt">Electron</span> Sources</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Khazanov, G. V.; Liemohn, M. W.; Kozyra, J. U.; Moore, T. E.</p> <p>1998-01-01</p> <p>Two time-dependent kinetic models of superthermal <span class="hlt">electron</span> <span class="hlt">transport</span> are combined to conduct global calculations of the nonthermal <span class="hlt">electron</span> distribution function throughout the inner magnetosphere. It is shown that the energy range of validity for this combined model extends down to the superthermal-thermal intersection at a few eV, allowing for the calculation of the en- tire distribution function and thus an accurate heating rate to the thermal plasma. Because of the linearity of the formulas, the source terms are separated to calculate the distributions from the various populations, namely photoelectrons (PEs) and plasma sheet <span class="hlt">electrons</span> (PSEs). These distributions are discussed in detail, examining the processes responsible for their formation in the various regions of the inner magnetosphere. It is shown that convection, corotation, and Coulomb collisions are the dominant processes in the formation of the PE distribution function and that PSEs are dominated by the interplay between the drift terms. Of note is that the PEs propagate around the nightside in a narrow channel at the edge of the plasmasphere as Coulomb collisions reduce the fluxes inside of this and convection compresses the flux tubes inward. These distributions are then recombined to show the development of the total superthermal <span class="hlt">electron</span> distribution function in the inner magnetosphere and their influence on the thermal plasma. PEs usually dominate the dayside heating, with integral energy fluxes to the ionosphere reaching 10(exp 10) eV/sq cm/s in the plasmasphere, while heating from the PSEs typically does not exceed 10(exp 8) eV/sq cm/s. On the nightside, the inner plasmasphere is usually unheated by superthermal <span class="hlt">electrons</span>. A feature of these combined spectra is that the distribution often has upward slopes with energy, particularly at the crossover from PE to PSE dominance, indicating that instabilities are possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800024817','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800024817"><span id="translatedtitle">Survey of the plasma <span class="hlt">electron</span> <span class="hlt">environment</span> of Jupiter: A view from Voyager</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scudder, J. D.; Sittler, E. C., Jr.; Bridge, H. S.</p> <p>1980-01-01</p> <p>The plasma <span class="hlt">environment</span> within Jupiter's bow shock is considered in terms of the in situ, calibrated <span class="hlt">electron</span> plasma measurements made between 10 eV and 5.95 keV by the Voyager plasma science experiment (PLS). Measurements were analyzed and corrected for spacecraft potential variations; the data were reduced to nearly model independent macroscopic parameters of the local <span class="hlt">electron</span> density and temperature. It is tentatively concluded that the radial temperature profile within the plasma sheet is caused by the intermixing of two different <span class="hlt">electron</span> populations that probably have different temporal histories and spatial paths to their local observation. The cool plasma source of the plasma sheet and spikes is probably the Io plasma torus and arrives in the plasma sheet as a result of flux tube interchange motions or other generalized <span class="hlt">transport</span> which can be accomplished without diverting the plasma from the centrifugal equator. The hot suprathermal populations in the plasma sheet have most recently come from the sparse, hot mid-latitude "bath" of <span class="hlt">electrons</span> which were directly observed juxtaposed to the plasma sheet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/319673','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/319673"><span id="translatedtitle"><span class="hlt">Electron</span> heat <span class="hlt">transport</span> in improved confinement discharges in DIII-D</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stallard, B.W.; Greenfield, C.M.; Staebler, G.M.</p> <p>1999-01-01</p> <p>In DIII-D tokamak plasmas with an internal <span class="hlt">transport</span> barrier (ITB), the comparison of gyrokinetic linear stability (GKS) predictions with experiments in both low and strong negative magnetic shear plasmas provide improved understanding for <span class="hlt">electron</span> thermal <span class="hlt">transport</span> within the plasma. Within a limited region just inside the ITB, the <span class="hlt">electron</span> temperature gradient (ETG) modes appear to control the <span class="hlt">electron</span> temperature gradient and, consequently, the <span class="hlt">electron</span> thermal <span class="hlt">transport</span>. The increase in the <span class="hlt">electron</span> temperature gradient with more strongly negative magnetic shear is consistent with the increase in the ETG mode marginal gradient. Closer to the magnetic axis the T{sub e} profile flattens and the ETG modes are predicted to be stable. With additional core <span class="hlt">electron</span> heating, FIR scattering measurements near the axis show the presence of high k fluctuations (12 cm{sup {minus}1}), rotating in the <span class="hlt">electron</span> diamagnetic drift direction. This turbulence could impact <span class="hlt">electron</span> <span class="hlt">transport</span> and possibly also ion <span class="hlt">transport</span>. Thermal diffusivities for <span class="hlt">electrons</span>, and to a lesser degree ions, increase. The ETG mode can exist at this wavenumber, but it is computed to be robustly stable near the axis. Consequently, in the plasmas the authors have examined, calculations of drift wave linear stability do not explain the observed <span class="hlt">transport</span> near the axis in plasmas with or without additional <span class="hlt">electron</span> heating, and there are probably other processes controlling <span class="hlt">transport</span> in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARF53007F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARF53007F"><span id="translatedtitle">Complex wet-<span class="hlt">environments</span> in <span class="hlt">electronic</span>-structure calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fisicaro, Giuseppe; Genovese, Luigi; Andreussi, Oliviero; Marzari, Nicola; Goedecker, Stefan</p> <p></p> <p>The computational study of chemical reactions in complex, wet <span class="hlt">environments</span> is critical for applications in many fields. It is often essential to study chemical reactions in the presence of an applied electrochemical potentials, including complex electrostatic screening coming from the solvent. In the present work we present a solver to handle both the Generalized Poisson and the Poisson-Boltzmann equation. A preconditioned conjugate gradient (PCG) method has been implemented for the Generalized Poisson and the linear regime of the Poisson-Boltzmann, allowing to solve iteratively the minimization problem with some ten iterations. On the other hand, a self-consistent procedure enables us to solve the Poisson-Boltzmann problem. The algorithms take advantage of a preconditioning procedure based on the BigDFT Poisson solver for the standard Poisson equation. They exhibit very high accuracy and parallel efficiency, and allow different boundary conditions, including surfaces. The solver has been integrated into the BigDFT and Quantum-ESPRESSO <span class="hlt">electronic</span>-structure packages and it will be released as a independent program, suitable for integration in other codes. We present test calculations for large proteins to demonstrate efficiency and performances. This work was done within the PASC and NCCR MARVEL projects. Computer resources were provided by the Swiss National Supercomputing Centre (CSCS) under Project ID s499. LG acknowledges also support from the EXTMOS EU project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED124397.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED124397.pdf"><span id="translatedtitle">Impact of <span class="hlt">Transportation</span> on the <span class="hlt">Environment</span> and Quality of Life.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Schuster, James J.</p> <p></p> <p>This paper discusses the changing role of civil engineers in developed nations. <span class="hlt">Transportation</span> facilities generally follow a four phase approach before construction: long range systems planning, corridor location study, design location study, and final preparation of plans. Traditional engineering education emphasized the latter two phases but now…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5021927','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5021927"><span id="translatedtitle"><span class="hlt">Transportation</span> of radionuclides in urban <span class="hlt">environs</span>: draft environmental assessment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Finley, N.C.; Aldrich, D.C.; Daniel, S.L.; Ericson, D.M.; Henning-Sachs, C.; Kaestner, P.C.; Ortiz, N.R.; Sheldon, D.D.; Taylor, J.M.</p> <p>1980-07-01</p> <p>This report assesses the environmental consequences of the <span class="hlt">transportation</span> of radioactive materials in densely populated urban areas, including estimates of the radiological, nonradiological, and social impacts arising from this process. The chapters of the report and the appendices which follow detail the methodology and results for each of four causative event categories: incident free <span class="hlt">transport</span>, vehicular accidents, human errors or deviations from accepted quality assurance practices, and sabotage or malevolent acts. The numerical results are expressed in terms of the expected radiological and economic impacts from each. Following these discussions, alternatives to the current <span class="hlt">transport</span> practice are considered. Then, the detailed analysis is extended from a limited area of New York city to other urban areas. The appendices contain the data bases and specific models used to evaluate these impacts, as well as discussions of chemical toxicity and the social impacts of radioactive material <span class="hlt">transport</span> in urban areas. The latter are evaluated for each causative event category in terms of psychological, sociological, political, legal, and organizational impacts. The report is followed by an extensive bibliography covering the many fields of study which were required in performing the analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986WRR....22..519K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986WRR....22..519K"><span id="translatedtitle">Groundwater <span class="hlt">Transport</span> of Strontium 90 in a Glacial Outwash <span class="hlt">Environment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kipp, Kenneth L., Jr.; Stollenwerk, Kenneth G.; Grove, David B.</p> <p>1986-04-01</p> <p>As part of the investigation of groundwater contamination at a uranium-scrap recovery plant at Wood River Junction, Rhode Island, laboratory experiments led to the development of a model for predicting the <span class="hlt">transport</span> of strontium 90 in glacial outwash sediments based on an approximate mechanism for ion exchange. The multicomponent system was simplified to two components by regarding all exchangeable cations other than strontium 90 as a single component. The binary ion-exchange parameter was a function of the variable, total ion concentration. A one-dimensional solute <span class="hlt">transport</span> model was formulated to evaluate the time necessary for natural groundwater flow to remove the strontium 90 contamination plume from the groundwater system to the Pawcatuck River. The finite difference <span class="hlt">transport</span> equations were solved sequentially for total ion concentrations, then strontium 90 concentrations. Clay-free quartz and feldspar sands at the study site have little potential for strontium 90 sorption, and high calcium, magnesium, and sodium concentrations compete for the few ion exchange sites. As the total ion concentration plume moves out of the system, ion exchange of strontium 90 increases, reducing the strontium 90 concentration in the groundwater. Cleanout times predicted using the binary ion exchange mechanism were about two thirds of those predicted using a constant distribution coefficient. It is suggested that this type of model can simulate solute <span class="hlt">transport</span> more realistically in many groundwater systems where the total ion concentration is not constant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040081287&hterms=living+environment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dliving%2Benvironment','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040081287&hterms=living+environment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dliving%2Benvironment"><span id="translatedtitle">The Space Radiation <span class="hlt">Environment</span> and Its Implication for Designing Reliable <span class="hlt">Electronic</span> Systems: A NASA Perspective</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>LaBel, Kenneth A.</p> <p>2004-01-01</p> <p>The contents include the following: The space radiation <span class="hlt">environment</span>. The effects on <span class="hlt">electronics</span>. The <span class="hlt">environment</span> in action NASA approaches to commercial <span class="hlt">electronics</span>: flight projects; and proactive research. Living with a star space <span class="hlt">environment</span> testbed status. Final thoughts: atomic interactions; direct ionization; interaction with nucleus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040129706','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040129706"><span id="translatedtitle">MGS MAG/ER Data Analysis Using a Time and Magnetic Field Dependent <span class="hlt">Electron</span> <span class="hlt">Transport</span> Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liemohn, Michael W.; Mitchell, David L.; Nagy, A. F.</p> <p>2004-01-01</p> <p>The goal of that project was to examine certain details about the dayside <span class="hlt">electron</span> <span class="hlt">environment</span> at Mars as seen by the Mars Global Surveyor (MGS) magnetometer/<span class="hlt">electron</span> reflectometer (MAG/ER) instrument. Specifically, we stated that we would use the Khazanov and Liemohn (K&L) kinetic <span class="hlt">electron</span> <span class="hlt">transport</span> model to analyze features in the observations. This code includes a non-uniform magnetic field and time-dependence in the result (different from most other models of this type). It was originally developed for <span class="hlt">electron</span> motion along field lines in the Earth's magnetosphere (between conjugate ionospheres), and is thus quite appropriate for application to the Mars magnetic field scenario. Numerous code developments were implemented and the Mars version of the K&L model is fully operational. Initial results from this code have focused on the examination of MGS MAG/ER observations in the crustal field region when it is on the dayside. After several presentations at scientific meetings, this study culminated in a JGR publication last year.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=adobe&pg=3&id=EJ1068668','ERIC'); return false;" href="http://eric.ed.gov/?q=adobe&pg=3&id=EJ1068668"><span id="translatedtitle">Using Adobe Flash Animations of <span class="hlt">Electron</span> <span class="hlt">Transport</span> Chain to Teach and Learn Biochemistry</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Teplá, Milada; Klímová, Helena</p> <p>2015-01-01</p> <p>Teaching the subject of the <span class="hlt">electron</span> <span class="hlt">transport</span> chain is one of the most challenging aspects of the chemistry curriculum at the high school level. This article presents an educational program called "<span class="hlt">Electron</span> <span class="hlt">Transport</span> Chain" which consists of 14 visual animations including a biochemistry quiz. The program was created in the Adobe Flash…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1069163','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1069163"><span id="translatedtitle"><span class="hlt">Transportation</span> Energy Futures Series: Effects of the Built <span class="hlt">Environment</span> on <span class="hlt">Transportation</span>: Energy Use, Greenhouse Gas Emissions, and Other Factors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Porter, C. D.; Brown, A.; Dunphy, R. T.; Vimmerstedt, L.</p> <p>2013-03-01</p> <p>Planning initiatives in many regions and communities aim to reduce <span class="hlt">transportation</span> energy use, decrease emissions, and achieve related environmental benefits by changing land use. This report reviews and summarizes findings from existing literature on the relationship between the built <span class="hlt">environment</span> and <span class="hlt">transportation</span> energy use and greenhouse gas emissions, identifying results trends as well as potential future actions. The indirect influence of federal <span class="hlt">transportation</span> and housing policies, as well as the direct impact of municipal regulation on land use are examined for their effect on <span class="hlt">transportation</span> patterns and energy use. Special attention is given to the 'four D' factors of density, diversity, design and accessibility. The report concludes that policy-driven changes to the built <span class="hlt">environment</span> could reduce <span class="hlt">transportation</span> energy and GHG emissions from less than 1% to as much as 10% by 2050, the equivalent of 16%-18% of present-day urban light-duty-vehicle travel. This is one of a series of reports produced as a result of the <span class="hlt">Transportation</span> Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to <span class="hlt">transportation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1219931','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1219931"><span id="translatedtitle"><span class="hlt">Transportation</span> Energy Futures Series. Effects of the Built <span class="hlt">Environment</span> on <span class="hlt">Transportation</span>. Energy Use, Greenhouse Gas Emissions, and Other Factors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Porter, C. D.; Brown, A.; Dunphy, R. T.; Vimmerstedt, L.</p> <p>2013-03-15</p> <p>Planning initiatives in many regions and communities aim to reduce <span class="hlt">transportation</span> energy use, decrease emissions, and achieve related environmental benefits by changing land use. This report reviews and summarizes findings from existing literature on the relationship between the built <span class="hlt">environment</span> and <span class="hlt">transportation</span> energy use and greenhouse gas emissions, identifying results trends as well as potential future actions. The indirect influence of federal <span class="hlt">transportation</span> and housing policies, as well as the direct impact of municipal regulation on land use are examined for their effect on <span class="hlt">transportation</span> patterns and energy use. Special attention is given to the 'four D' factors of density, diversity, design and accessibility. The report concludes that policy-driven changes to the built <span class="hlt">environment</span> could reduce <span class="hlt">transportation</span> energy and GHG emissions from less than 1% to as much as 10% by 2050, the equivalent of 16%-18% of present-day urban light-duty-vehicle travel. This is one of a series of reports produced as a result of the <span class="hlt">Transportation</span> Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to <span class="hlt">transportation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title41-vol3/pdf/CFR-2010-title41-vol3-sec102-118-65.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title41-vol3/pdf/CFR-2010-title41-vol3-sec102-118-65.pdf"><span id="translatedtitle">41 CFR 102-118.65 - Can my agency receive <span class="hlt">electronic</span> billing for payment of <span class="hlt">transportation</span> services?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... <span class="hlt">electronic</span> billing for payment of <span class="hlt">transportation</span> services? 102-118.65 Section 102-118.65 Public Contracts and... <span class="hlt">Transportation</span> Services § 102-118.65 Can my agency receive <span class="hlt">electronic</span> billing for payment of <span class="hlt">transportation</span>... to use <span class="hlt">electronic</span> billing for the procurement and billing of <span class="hlt">transportation</span> services....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/411733','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/411733"><span id="translatedtitle">Multigroup Boltzmann-Fokker-Planck <span class="hlt">electron</span>-photon <span class="hlt">transport</span> capability in MCNP</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Adams, K.J.; Hart, M.</p> <p>1995-12-31</p> <p>The MCNP code system has a robust multigroup <span class="hlt">transport</span> capability that includes a Boltzmann-Fokker-Planck (MGBFP) <span class="hlt">transport</span> algorithm to perform coupled <span class="hlt">electron</span>-photon or other coupled charged and neutral particle <span class="hlt">transport</span> in either a forward or adjoint mode. This paper discusses this capability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014NJPh...16g3014T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014NJPh...16g3014T&link_type=ABSTRACT"><span id="translatedtitle">A reduced model for relativistic <span class="hlt">electron</span> beam <span class="hlt">transport</span> in solids and dense plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Touati, M.; Feugeas, J.-L.; Nicolaï, Ph; Santos, J. J.; Gremillet, L.; Tikhonchuk, V. T.</p> <p>2014-07-01</p> <p>A hybrid reduced model for relativistic <span class="hlt">electron</span> beam <span class="hlt">transport</span> based on the angular moments of the relativistic kinetic equation with a special closure is presented. It takes into account collective effects with the self-generated electromagnetic fields as well as collisional effects with the slowing down of the relativistic <span class="hlt">electrons</span> by plasmons, bound and free <span class="hlt">electrons</span> and their angular scattering on both ions and <span class="hlt">electrons</span>. This model allows for fast computations of relativistic <span class="hlt">electron</span> beam <span class="hlt">transport</span> while describing their energy distribution evolution. Despite the loss of information concerning the angular distribution of the <span class="hlt">electron</span> beam, the model reproduces analytical estimates in the academic case of a monodirectional and monoenergetic <span class="hlt">electron</span> beam propagating through a warm and dense plasma and hybrid particle-in-cell simulation results in a realistic laser-generated <span class="hlt">electron</span> beam <span class="hlt">transport</span> case.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3572443','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3572443"><span id="translatedtitle">Hot <span class="hlt">electron</span> <span class="hlt">transport</span> in a strongly correlated transition-metal oxide</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rana, Kumari Gaurav; Yajima, Takeaki; Parui, Subir; Kemper, Alexander F.; Devereaux, Thomas P.; Hikita, Yasuyuki; Hwang, Harold Y.; Banerjee, Tamalika</p> <p>2013-01-01</p> <p>Oxide heterointerfaces are ideal for investigating strong correlation effects to <span class="hlt">electron</span> <span class="hlt">transport</span>, relevant for oxide-<span class="hlt">electronics</span>. Using hot-<span class="hlt">electrons</span>, we probe <span class="hlt">electron</span> <span class="hlt">transport</span> perpendicular to the La0.7Sr0.3MnO3 (LSMO)- Nb-doped SrTiO3 (Nb:STO) interface and find the characteristic hot-<span class="hlt">electron</span> attenuation length in LSMO to be 1.48 ± 0.10 unit cells (u.c.) at −1.9 V, increasing to 2.02 ± 0.16 u.c. at −1.3 V at room temperature. Theoretical analysis of this energy dispersion reveals the dominance of <span class="hlt">electron-electron</span> and polaron scattering. Direct visualization of the local <span class="hlt">electron</span> <span class="hlt">transport</span> shows different transmission at the terraces and at the step-edges. PMID:23429420</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1096262','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1096262"><span id="translatedtitle">Modeling <span class="hlt">electron</span> <span class="hlt">transport</span> in the presence of electric and magnetic fields.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fan, Wesley C.; Drumm, Clifton Russell; Pautz, Shawn D.; Turner, C. David</p> <p>2013-09-01</p> <p>This report describes the theoretical background on modeling <span class="hlt">electron</span> <span class="hlt">transport</span> in the presence of electric and magnetic fields by incorporating the effects of the Lorentz force on <span class="hlt">electron</span> motion into the Boltzmann <span class="hlt">transport</span> equation. Electromagnetic fields alter the <span class="hlt">electron</span> energy and trajectory continuously, and these effects can be characterized mathematically by differential operators in terms of <span class="hlt">electron</span> energy and direction. Numerical solution techniques, based on the discrete-ordinates and finite-element methods, are developed and implemented in an existing radiation <span class="hlt">transport</span> code, SCEPTRE.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070020429','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070020429"><span id="translatedtitle">Radiation-Hardened <span class="hlt">Electronics</span> for the Space <span class="hlt">Environment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Keys, Andrew S.; Watson, Michael D.</p> <p>2007-01-01</p> <p>RHESE covers a broad range of technology areas and products. - Radiation Hardened <span class="hlt">Electronics</span> - High Performance Processing - Reconfigurable Computing - Radiation Environmental Effects Modeling - Low Temperature Radiation Hardened <span class="hlt">Electronics</span>. RHESE has aligned with currently defined customer needs. RHESE is leveraging/advancing SOA space <span class="hlt">electronics</span>, not duplicating. - Awareness of radiation-related activities through out government and industry allow advancement rather than duplication of capabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.G1179S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.G1179S"><span id="translatedtitle">The <span class="hlt">electronic</span> and <span class="hlt">transport</span> properties of monolayer transition metal dichalcogenides: a complex band structure analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Szczesniak, Dominik</p> <p></p> <p>Recently, monolayer transition metal dichalcogenides have attracted much attention due to their potential use in both nano- and opto-<span class="hlt">electronics</span>. In such applications, the <span class="hlt">electronic</span> and <span class="hlt">transport</span> properties of group-VIB transition metal dichalcogenides (MX2 , where M=Mo, W; X=S, Se, Te) are particularly important. Herein, new insight into these properties is presented by studying the complex band structures (CBS's) of MX2 monolayers while accounting for spin-orbit coupling effects. By using the symmetry-based tight-binding model a nonlinear generalized eigenvalue problem for CBS's is obtained. An efficient method for solving such class of problems is presented and gives a complete set of physically relevant solutions. Next, these solutions are characterized and classified into propagating and evanescent states, where the latter states present not only monotonic but also oscillatory decay character. It is observed that some of the oscillatory evanescent states create characteristic complex loops at the direct band gaps, which describe the tunneling currents in the MX2 materials. The importance of CBS's and tunneling currents is demonstrated by the analysis of the quantum <span class="hlt">transport</span> across MX2 monolayers within phase field matching theory. Present work has been prepared within the Qatar Energy and <span class="hlt">Environment</span> Research Institute (QEERI) grand challenge ATHLOC project (Project No. QEERI- GC-3008).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011NIMPB.269..232B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011NIMPB.269..232B"><span id="translatedtitle">A deterministic <span class="hlt">electron</span>, photon, proton and heavy ion <span class="hlt">transport</span> suite for the study of the Jovian moon Europa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Badavi, Francis F.; Blattnig, Steve R.; Atwell, William; Nealy, John E.; Norman, Ryan B.</p> <p>2011-02-01</p> <p>A Langley research center (LaRC) developed deterministic suite of radiation <span class="hlt">transport</span> codes describing the propagation of <span class="hlt">electron</span>, photon, proton and heavy ion in condensed media is used to simulate the exposure from the spectral distribution of the aforementioned particles in the Jovian radiation <span class="hlt">environment</span>. Based on the measurements by the Galileo probe (1995-2003) heavy ion counter (HIC), the choice of trapped heavy ions is limited to carbon, oxygen and sulfur (COS). The deterministic particle <span class="hlt">transport</span> suite consists of a coupled <span class="hlt">electron</span> photon algorithm (CEPTRN) and a coupled light heavy ion algorithm (HZETRN). The primary purpose for the development of the <span class="hlt">transport</span> suite is to provide a means to the spacecraft design community to rapidly perform numerous repetitive calculations essential for <span class="hlt">electron</span>, photon, proton and heavy ion exposure assessment in a complex space structure. In this paper, the reference radiation <span class="hlt">environment</span> of the Galilean satellite Europa is used as a representative boundary condition to show the capabilities of the <span class="hlt">transport</span> suite. While the <span class="hlt">transport</span> suite can directly access the output <span class="hlt">electron</span> and proton spectra of the Jovian <span class="hlt">environment</span> as generated by the jet propulsion laboratory (JPL) Galileo interim radiation <span class="hlt">electron</span> (GIRE) model of 2003; for the sake of relevance to the upcoming Europa Jupiter system mission (EJSM), the JPL provided Europa mission fluence spectrum, is used to produce the corresponding depth dose curve in silicon behind a default aluminum shield of 100 mils (˜0.7 g/cm2). The <span class="hlt">transport</span> suite can also accept a geometry describing ray traced thickness file from a computer aided design (CAD) package and calculate the total ionizing dose (TID) at a specific target point within the interior of the vehicle. In that regard, using a low fidelity CAD model of the Galileo probe generated by the authors, the <span class="hlt">transport</span> suite was verified versus Monte Carlo (MC) simulation for orbits JOI-J35 of the Galileo probe</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=318201&keyword=job&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=68428032&CFTOKEN=53228849','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=318201&keyword=job&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=68428032&CFTOKEN=53228849"><span id="translatedtitle">The association between green neighborhood <span class="hlt">environments</span> and active <span class="hlt">transportation</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Background: Urban nature is an important aspect of health-promoting <span class="hlt">environments</span>. In particular, street trees and green space can provide a low cost approach to improving public health by promoting physical activity, improving mental health, and facilitating social cohesion. Acti...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23698325','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23698325"><span id="translatedtitle">Stepping stones in the <span class="hlt">electron</span> <span class="hlt">transport</span> from cells to electrodes in Geobacter sulfurreducens biofilms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bonanni, Pablo Sebastián; Massazza, Diego; Busalmen, Juan Pablo</p> <p>2013-07-01</p> <p>Geobacter sulfurreducens bacteria grow on biofilms and have the particular ability of using polarized electrodes as the final <span class="hlt">electron</span> acceptor of their respiratory chain. In these biofilms, <span class="hlt">electrons</span> are <span class="hlt">transported</span> through distances of more than 50 μm before reaching the electrode. The way in which <span class="hlt">electrons</span> are <span class="hlt">transported</span> across the biofilm matrix through such large distances remains under intense discussion. None of the two mechanisms proposed for explaining the process, <span class="hlt">electron</span> hopping through outer membrane cytochromes and metallic like conduction through conductive PilA filaments, can account for all the experimental evidence collected so far. Aiming at providing new elements for understanding the basis for <span class="hlt">electron</span> <span class="hlt">transport</span>, in this perspective article we present a modelled structure of Geobacter pilus. Its analysis in combination with already existing experimental evidence gives support to the proposal of the "stepping stone" mechanism, in which the combined action of pili and cytochromes allows long range <span class="hlt">electron</span> <span class="hlt">transport</span> through the biofilm. PMID:23698325</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4734430','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4734430"><span id="translatedtitle">Probing the local <span class="hlt">environment</span> of a single OPE3 molecule using inelastic tunneling <span class="hlt">electron</span> spectroscopy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>Summary We study single-molecule oligo(phenylene ethynylene)dithiol junctions by means of inelastic <span class="hlt">electron</span> tunneling spectroscopy (IETS). The molecule is contacted with gold nano-electrodes formed with the mechanically controllable break junction technique. We record the IETS spectrum of the molecule from direct current measurements, both as a function of time and electrode separation. We find that for fixed electrode separation the molecule switches between various configurations, which are characterized by different IETS spectra. Similar variations in the IETS signal are observed during atomic rearrangements upon stretching of the molecular junction. Using quantum chemistry calculations, we identity some of the vibrational modes which constitute a chemical fingerprint of the molecule. In addition, changes can be attributed to rearrangements of the local molecular <span class="hlt">environment</span>, in particular at the molecule–electrode interface. This study shows the importance of taking into account the interaction with the electrodes when describing inelastic contributions to <span class="hlt">transport</span> through single-molecule junctions. PMID:26885460</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED423842.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED423842.pdf"><span id="translatedtitle">Creating <span class="hlt">Electronic</span> Learning <span class="hlt">Environments</span>: Games, Flow, and the User Interface.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Jones, Marshall G.</p> <p></p> <p>A difficult task in creating rich, exploratory interactive learning <span class="hlt">environments</span> is building an <span class="hlt">environment</span> that is truly engaging. Engagement can be defined as the nexus of intrinsic knowledge and/or interest and external stimuli that promote the initial interest in, and continued use of a computer-based learning <span class="hlt">environment</span>. Complete and total…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26382153','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26382153"><span id="translatedtitle">Bacterial <span class="hlt">transport</span> of colloids in liquid crystalline <span class="hlt">environments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Trivedi, Rishi R; Maeda, Rina; Abbott, Nicholas L; Spagnolie, Saverio E; Weibel, Douglas B</p> <p>2015-11-21</p> <p>We describe the controlled <span class="hlt">transport</span> and delivery of non-motile eukaryotic cells and polymer microparticles by swimming bacteria suspended in nematic liquid crystals. The bacteria push reversibly attached cargo in a stable, unidirectional path (or along a complex patterned director field) over exceptionally long distances. Numerical simulations and analytical predictions for swimming speeds provide a mechanistic insight into the hydrodynamics of the system. This study lays the foundation for using cargo-carrying bacteria in engineering applications and for understanding interspecies interactions in polymicrobial communities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990GeoRL..17..799R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990GeoRL..17..799R"><span id="translatedtitle">The occurrence and <span class="hlt">transport</span> of radon in the natural <span class="hlt">environment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reimer, G. M.</p> <p>1990-05-01</p> <p>Radon—a colorless, odorless, tasteless, radioactive gas known to accumulate in homes. Within the last two years, those words have appeared in probably every newspaper in the country, informing the public that they may have an increased risk of lung cancer due to exposure to radon. Although the actual health risks of the slightly elevated concentrations found in the vast majority of homes is a matter of current scientific study, there are clearly some areas of the country where indoor levels and individual exposures can approach those found in underground mines. In these cases, the risks are not in doubt, but questions concerning the occurrence and <span class="hlt">transport</span> of radon abound.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H21A1327M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H21A1327M"><span id="translatedtitle">Adaptive Mesh Refinement in Reactive <span class="hlt">Transport</span> Modeling of Subsurface <span class="hlt">Environments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Molins, S.; Day, M.; Trebotich, D.; Graves, D. T.</p> <p>2015-12-01</p> <p>Adaptive mesh refinement (AMR) is a numerical technique for locally adjusting the resolution of computational grids. AMR makes it possible to superimpose levels of finer grids on the global computational grid in an adaptive manner allowing for more accurate calculations locally. AMR codes rely on the fundamental concept that the solution can be computed in different regions of the domain with different spatial resolutions. AMR codes have been applied to a wide range of problem including (but not limited to): fully compressible hydrodynamics, astrophysical flows, cosmological applications, combustion, blood flow, heat transfer in nuclear reactors, and land ice and atmospheric models for climate. In subsurface applications, in particular, reactive <span class="hlt">transport</span> modeling, AMR may be particularly useful in accurately capturing concentration gradients (hence, reaction rates) that develop in localized areas of the simulation domain. Accurate evaluation of reaction rates is critical in many subsurface applications. In this contribution, we will discuss recent applications that bring to bear AMR capabilities on reactive <span class="hlt">transport</span> problems from the pore scale to the flood plain scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3996691','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3996691"><span id="translatedtitle">Methanotrophic archaea possessing diverging methane-oxidizing and <span class="hlt">electron-transporting</span> pathways</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Feng-Ping; Zhang, Yu; Chen, Ying; He, Ying; Qi, Ji; Hinrichs, Kai-Uwe; Zhang, Xin-Xu; Xiao, Xiang; Boon, Nico</p> <p>2014-01-01</p> <p>Anaerobic oxidation of methane (AOM) is a crucial process limiting the flux of methane from marine <span class="hlt">environments</span> to the atmosphere. The process is thought to be mediated by three groups of uncultivated methane-oxidizing archaea (ANME-1, 2 and 3). Although the responsible microbes have been intensively studied for more than a decade, central mechanistic details remain unresolved. On the basis of an integrated analysis of both environmental metatranscriptome and single-aggregate genome of a highly active AOM enrichment dominated by ANME-2a, we provide evidence for a complete and functioning AOM pathway in ANME-2a. All genes required for performing the seven steps of methanogenesis from CO2 were found present and actively expressed. Meanwhile, genes for energy conservation and <span class="hlt">electron</span> <span class="hlt">transportation</span> including those encoding F420H2 dehydrogenase (Fpo), the cytoplasmic and membrane-associated Coenzyme B–Coenzyme M heterodisulfide (CoB-S-SCoM) reductase (HdrABC, HdrDE), cytochrome C and the Rhodobacter nitrogen fixation (Rnf) complex were identified and expressed, whereas genes encoding for hydrogenases were absent. Thus, ANME-2a is likely performing AOM through a complete reversal of methanogenesis from CO2 reduction without involvement of canonical hydrogenase. ANME-2a is demonstrated to possess versatile <span class="hlt">electron</span> transfer pathways that would provide the organism with more flexibility in substrate utilization and capacity for rapid adjustment to fluctuating <span class="hlt">environments</span>. This work lays the foundation for understanding the environmental niche differentiation, physiology and evolution of different ANME subgroups. PMID:24335827</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24671086','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24671086"><span id="translatedtitle">Natural occurrence of microbial sulphur oxidation by long-range <span class="hlt">electron</span> <span class="hlt">transport</span> in the seafloor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Malkin, Sairah Y; Rao, Alexandra M F; Seitaj, Dorina; Vasquez-Cardenas, Diana; Zetsche, Eva-Maria; Hidalgo-Martinez, Silvia; Boschker, Henricus T S; Meysman, Filip J R</p> <p>2014-09-01</p> <p>Recently, a novel mode of sulphur oxidation was described in marine sediments, in which sulphide oxidation in deeper anoxic layers was electrically coupled to oxygen reduction at the sediment surface. Subsequent experimental evidence identified that long filamentous bacteria belonging to the family Desulfobulbaceae likely mediated the <span class="hlt">electron</span> <span class="hlt">transport</span> across the centimetre-scale distances. Such long-range <span class="hlt">electron</span> transfer challenges some long-held views in microbial ecology and could have profound implications for sulphur cycling in marine sediments. But, so far, this process of electrogenic sulphur oxidation has been documented only in laboratory experiments and so its imprint on the seafloor remains unknown. Here we show that the geochemical signature of electrogenic sulphur oxidation occurs in a variety of coastal sediment <span class="hlt">environments</span>, including a salt marsh, a seasonally hypoxic basin, and a subtidal coastal mud plain. In all cases, electrogenic sulphur oxidation was detected together with an abundance of Desulfobulbaceae filaments. Complementary laboratory experiments in intertidal sands demonstrated that mechanical disturbance by bioturbating fauna destroys the electrogenic sulphur oxidation signal. A survey of published geochemical data and 16S rRNA gene sequences identified that electrogenic sulphide oxidation is likely present in a variety of marine sediments with high sulphide generation and restricted bioturbation, such as mangrove swamps, aquaculture areas, seasonally hypoxic basins, cold sulphide seeps and possibly hydrothermal vent <span class="hlt">environments</span>. This study shows for the first time that electrogenic sulphur oxidation occurs in a wide range of marine sediments and that bioturbation may exert a dominant control on its natural distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7252688','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7252688"><span id="translatedtitle">Nonlocal <span class="hlt">electron</span> <span class="hlt">transport</span> in the presence of high-intensity laser irradiation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Epperlein, E.M.; Short, R.W. )</p> <p>1994-08-01</p> <p>We investigate <span class="hlt">electron</span> <span class="hlt">transport</span> in a plasma heated by spatially modulated laser irradiation. When the heating rate is greater than the <span class="hlt">electron-electron</span> collision rate, the thermal conductivity is reduced by a factor of 3 to 4 from the Spitzer-Haerm [Phys. Rev. 89, 977 (1953)] value for [ital K][lambda][sub [ital e</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27420809','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27420809"><span id="translatedtitle">Competition of static magnetic and dynamic photon forces in <span class="hlt">electronic</span> <span class="hlt">transport</span> through a quantum dot.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rauf Abdullah, Nzar; Tang, Chi-Shung; Manolescu, Andrei; Gudmundsson, Vidar</p> <p>2016-09-21</p> <p>We investigate theoretically the balance of the static magnetic and the dynamical photon forces in the <span class="hlt">electron</span> <span class="hlt">transport</span> through a quantum dot in a photon cavity with a single photon mode. The quantum dot system is connected to external leads and the total system is exposed to a static perpendicular magnetic field. We explore the <span class="hlt">transport</span> characteristics through the system by tuning the ratio, [Formula: see text], between the photon energy, [Formula: see text], and the cyclotron energy, [Formula: see text]. Enhancement in the <span class="hlt">electron</span> <span class="hlt">transport</span> with increasing <span class="hlt">electron</span>-photon coupling is observed when [Formula: see text]. In this case the photon field dominates and stretches the <span class="hlt">electron</span> charge distribution in the quantum dot, extending it towards the contact area for the leads. Suppression in the <span class="hlt">electron</span> <span class="hlt">transport</span> is found when [Formula: see text], as the external magnetic field causes circular confinement of the charge density around the dot.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25680580','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25680580"><span id="translatedtitle">Induction events and short-term regulation of <span class="hlt">electron</span> <span class="hlt">transport</span> in chloroplasts: an overview.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tikhonov, Alexander N</p> <p>2015-08-01</p> <p>Regulation of photosynthetic <span class="hlt">electron</span> <span class="hlt">transport</span> at different levels of structural and functional organization of photosynthetic apparatus provides efficient performance of oxygenic photosynthesis in plants. This review begins with a brief overview of the chloroplast <span class="hlt">electron</span> <span class="hlt">transport</span> chain. Then two noninvasive biophysical methods (measurements of slow induction of chlorophyll a fluorescence and EPR signals of oxidized P700 centers) are exemplified to illustrate the possibility of monitoring induction events in chloroplasts in vivo and in situ. Induction events in chloroplasts are considered and briefly discussed in the context of short-term mechanisms of the following regulatory processes: (i) pH-dependent control of the intersystem <span class="hlt">electron</span> <span class="hlt">transport</span>; (ii) the light-induced activation of the Calvin-Benson cycle; (iii) optimization of <span class="hlt">electron</span> <span class="hlt">transport</span> due to fitting alternative pathways of <span class="hlt">electron</span> flow and partitioning light energy between photosystems I and II; and (iv) the light-induced remodeling of photosynthetic apparatus and thylakoid membranes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27420809','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27420809"><span id="translatedtitle">Competition of static magnetic and dynamic photon forces in <span class="hlt">electronic</span> <span class="hlt">transport</span> through a quantum dot.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rauf Abdullah, Nzar; Tang, Chi-Shung; Manolescu, Andrei; Gudmundsson, Vidar</p> <p>2016-09-21</p> <p>We investigate theoretically the balance of the static magnetic and the dynamical photon forces in the <span class="hlt">electron</span> <span class="hlt">transport</span> through a quantum dot in a photon cavity with a single photon mode. The quantum dot system is connected to external leads and the total system is exposed to a static perpendicular magnetic field. We explore the <span class="hlt">transport</span> characteristics through the system by tuning the ratio, [Formula: see text], between the photon energy, [Formula: see text], and the cyclotron energy, [Formula: see text]. Enhancement in the <span class="hlt">electron</span> <span class="hlt">transport</span> with increasing <span class="hlt">electron</span>-photon coupling is observed when [Formula: see text]. In this case the photon field dominates and stretches the <span class="hlt">electron</span> charge distribution in the quantum dot, extending it towards the contact area for the leads. Suppression in the <span class="hlt">electron</span> <span class="hlt">transport</span> is found when [Formula: see text], as the external magnetic field causes circular confinement of the charge density around the dot. PMID:27420809</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26436251','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26436251"><span id="translatedtitle">Microbial <span class="hlt">Transport</span> and Fate in the Subsurface <span class="hlt">Environment</span>: Introduction to the Special Section.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bradford, Scott A; Schijven, Jack; Harter, Thomas</p> <p>2015-09-01</p> <p>Microorganisms constitute an almost exclusive form of life in the earth's subsurface <span class="hlt">environment</span> (not including caves), particularly at depths exceeding the soil horizon. While of broad interest to ecology and geology, scientific interest in the fate and <span class="hlt">transport</span> of microorganisms, particularly those introduced through the anthropogenic <span class="hlt">environment</span>, has focused on understanding the subsurface <span class="hlt">environment</span> as a pathway for human pathogens and on optimizing the use of microbial organisms for remediation of potable groundwater. This special section, inspired by the 2014 Ninth International Symposium for Subsurface Microbiology, brings together recent efforts to better understand the spatiotemporal occurrence of anthropogenic microbial groundwater contamination and the fate and <span class="hlt">transport</span> of microbes in the subsurface <span class="hlt">environment</span>: in soils, deep unsaturated zones, and within aquifer systems. Work includes field reconnaissance, controlled laboratory studies to improve our understanding of specific fate and <span class="hlt">transport</span> processes, and the development and application of improved mechanistic understanding of microbial fate and <span class="hlt">transport</span> processes in the subsurface <span class="hlt">environment</span>. The findings confirm and also challenge the limitations of our current understanding of highly complex microbial fate and <span class="hlt">transport</span> processes across spatiotemporal scales in the subsurface <span class="hlt">environment</span>; they also add to the increasing knowledge base to improve our ability to protect drinking water resources and perform in situ environmental remediation. PMID:26436251</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26436251','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26436251"><span id="translatedtitle">Microbial <span class="hlt">Transport</span> and Fate in the Subsurface <span class="hlt">Environment</span>: Introduction to the Special Section.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bradford, Scott A; Schijven, Jack; Harter, Thomas</p> <p>2015-09-01</p> <p>Microorganisms constitute an almost exclusive form of life in the earth's subsurface <span class="hlt">environment</span> (not including caves), particularly at depths exceeding the soil horizon. While of broad interest to ecology and geology, scientific interest in the fate and <span class="hlt">transport</span> of microorganisms, particularly those introduced through the anthropogenic <span class="hlt">environment</span>, has focused on understanding the subsurface <span class="hlt">environment</span> as a pathway for human pathogens and on optimizing the use of microbial organisms for remediation of potable groundwater. This special section, inspired by the 2014 Ninth International Symposium for Subsurface Microbiology, brings together recent efforts to better understand the spatiotemporal occurrence of anthropogenic microbial groundwater contamination and the fate and <span class="hlt">transport</span> of microbes in the subsurface <span class="hlt">environment</span>: in soils, deep unsaturated zones, and within aquifer systems. Work includes field reconnaissance, controlled laboratory studies to improve our understanding of specific fate and <span class="hlt">transport</span> processes, and the development and application of improved mechanistic understanding of microbial fate and <span class="hlt">transport</span> processes in the subsurface <span class="hlt">environment</span>. The findings confirm and also challenge the limitations of our current understanding of highly complex microbial fate and <span class="hlt">transport</span> processes across spatiotemporal scales in the subsurface <span class="hlt">environment</span>; they also add to the increasing knowledge base to improve our ability to protect drinking water resources and perform in situ environmental remediation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26595471','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26595471"><span id="translatedtitle">Linking the serotonin <span class="hlt">transporter</span> gene, family <span class="hlt">environments</span>, hippocampal volume and depression onset: A prospective imaging gene × <span class="hlt">environment</span> analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Little, Keriann; Olsson, Craig A; Youssef, George J; Whittle, Sarah; Simmons, Julian G; Yücel, Murat; Sheeber, Lisa B; Foley, Debra L; Allen, Nicholas B</p> <p>2015-11-01</p> <p>A single imaging gene-<span class="hlt">environment</span> (IGxE) framework that is able to simultaneously model genetic, neurobiological, and environmental influences on psychopathology outcomes is needed to improve understanding of how complex interrelationships between allelic variation, differences in neuroanatomy or neuroactivity, and environmental experience affect risk for psychiatric disorder. In a longitudinal study of adolescent development we demonstrate the utility of such an IGxE framework by testing whether variation in parental behavior at age 12 altered the strength of an imaging genetics pathway, involving an indirect association between allelic variation in the serotonin <span class="hlt">transporter</span> gene to variation in hippocampal volume and consequent onset of major depressive disorder by age 18. Results were consistent with the presence of an indirect effect of the serotonin <span class="hlt">transporter</span> S-allele on depression onset via smaller left and right hippocampal volumes that was significant only in family <span class="hlt">environments</span> involving either higher levels of parental aggression or lower levels of positive parenting. The previously reported finding of S-allele carriers' increased risk of depression in adverse <span class="hlt">environments</span> may, therefore, be partly because of the effects of these <span class="hlt">environments</span> on a neurobiological pathway from the serotonin <span class="hlt">transporter</span> gene to depression onset that proceeds through variation in hippocampal volume.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/211608','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/211608"><span id="translatedtitle">Conceptual study of <span class="hlt">electron</span> ripple injection for tokamak <span class="hlt">transport</span> control</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Choe, W.; Ono, M.; Chang, C.S.</p> <p>1995-08-01</p> <p>A non-intrusive method for inducing radial electric field based on <span class="hlt">electron</span> ripple injection is under development by the Princeton CDX-U group. The radial electric field is known to play an important role in the L-H and H-VH mode transition according to the recent theoretical and experimental research. It is therefore important to develop a non-intrusive tool to control the radial electric field profile in tokamak plasmas. The present technique utilizes externally-applied local magnetic ripple fields to trap <span class="hlt">electrons</span> at the edge, allowing them to penetrate towards the plasma center via {gradient}B and curvature drifts, causing the flux surfaces to charge up negatively. <span class="hlt">Electron</span> cyclotron resonance heating is utilized to increase the trapped population and the <span class="hlt">electron</span> drift velocity by raising the perpendicular energy of trapped <span class="hlt">electrons</span>. In order to quantify the effects of cyclotron resonance heating on <span class="hlt">electrons</span>, the temperature anisotropy of resonant <span class="hlt">electrons</span> in a tokamak plasma is calculated. For the calculation of anisotropic temperatures, energy moments of the bounce-averaged Fokker-Planck equation with a bi-Maxwellian distribution function for heated <span class="hlt">electrons</span> are solved, assuming a moderate wave power and a constant quasilinear diffusion coefficient. Simulation using a guiding-center orbit model have been performed to understand the behavior of suprathermal <span class="hlt">electrons</span> in the presence of ripple fields. Examples for CDX-U and ITER parameters are given.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SeScT..31k5004B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SeScT..31k5004B"><span id="translatedtitle">Monte Carlo study of <span class="hlt">electron</span> <span class="hlt">transport</span> in monolayer silicene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borowik, Piotr; Thobel, Jean-Luc; Adamowicz, Leszek</p> <p>2016-11-01</p> <p><span class="hlt">Electron</span> mobility and diffusion coefficients in monolayer silicene are calculated by Monte Carlo simulations using simplified band structure with linear energy bands. Results demonstrate reasonable agreement with the full-band Monte Carlo method in low applied electric field conditions. Negative differential resistivity is observed and an explanation of the origin of this effect is proposed. <span class="hlt">Electron</span> mobility and diffusion coefficients are studied in low applied electric field conditions. We demonstrate that a comparison of these parameter values can provide a good check that the calculation is correct. Low-field mobility in silicene exhibits {T}-3 temperature dependence for nondegenerate <span class="hlt">electron</span> gas conditions and {T}-1 for higher <span class="hlt">electron</span> concentrations, when degenerate conditions are imposed. It is demonstrated that to explain the relation between mobility and temperature in nondegenerate <span class="hlt">electron</span> gas the linearity of the band structure has to be taken into account. It is also found that <span class="hlt">electron-electron</span> scattering only slightly modifies low-field <span class="hlt">electron</span> mobility in degenerate <span class="hlt">electron</span> gas conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960021284&hterms=Energy+Solar+Wind&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DEnergy%2B%252B%2BSolar%2B%252B%2BWind','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960021284&hterms=Energy+Solar+Wind&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DEnergy%2B%252B%2BSolar%2B%252B%2BWind"><span id="translatedtitle"><span class="hlt">Electron</span> energy <span class="hlt">transport</span> in the solar wind: Ulysses observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scime, Earl; Gary, S. Peter; Phillips, J. L.; Corniileau-Wehrlin, N.; Solomon, J.</p> <p>1995-01-01</p> <p>The <span class="hlt">electron</span> heat flux in the solar wind has been measured by the Ulysses solar wind plasma experiment in the ecliptic from 1 to 5 AU and out of the ecliptic during the recently completed pass over the solar south pole and the ongoing pass over the solar north pole. Although the <span class="hlt">electron</span> heat flux contains only a fraction of the kinetic energy of the solar wind. the available energy is sufficient to account for the non-adiabatic expansion of the solar wind <span class="hlt">electrons</span>. The Ulysses measurements indicate that the <span class="hlt">electron</span> heat flux is actively dissipated in the solar wind. The exact mechanism or mechanisms is unknown. but a model based on the whistler heat flux instability predicts radial gradients for the <span class="hlt">electron</span> heat flux in good agreement with the data. We will present measurements of the correlation between wave activity measured by the unified radio and plasma experiment (URAP) and the <span class="hlt">electron</span> heat flux throughout the Ulysses mission. The goal is to determine if whistler waves are a good candidate for the observed <span class="hlt">electron</span> heat flux dissipation. The latitudinal gradients of the <span class="hlt">electron</span> heat flux. wave activity. and <span class="hlt">electron</span> pressure will be discussed in light of the changes in the magnetic field geometry from equator to poles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JaJAP..40.7072F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JaJAP..40.7072F"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">Transport</span> across Magnetic Filter in Negative Hydrogen Ion Source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fukano, Azusa; Ogasawara, Masatada</p> <p>2001-12-01</p> <p>Profiles of <span class="hlt">electron</span> temperature and number density in a negative-ion source are investigated theoretically. Spatial dependence over the magnetic filter region is obtained using the equations of <span class="hlt">electron</span> flux and <span class="hlt">electron</span> heat flux that include the effect of interference of forces by the density gradient and temperature gradient. Due to the effect of the magnetic filter, temperature and density of the <span class="hlt">electron</span> decrease from the source chamber to the extraction chamber, and the decrease depends on the magnitude of the magnetic flux. The effect of the magnetic filter on the production and destruction rates of the negative hydrogen ion is examined. The reaction rate for the dissociative attachment reaction which produces the negative hydrogen ion increases with the decrease of the <span class="hlt">electron</span> temperature. However, the production rate per one vibrationally excited hydrogen molecule decreases with the decrease of <span class="hlt">electron</span> density. On the other hand, the destruction probability of the negative ion by the <span class="hlt">electron</span> detachment reaction decreases significantly by the decrease of the <span class="hlt">electron</span> density and temperature. The magnetic filter does not enhance the production of the negative hydrogen ion, but it reduces the destruction of the negative ion because of the decrease of the <span class="hlt">electron</span> density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApPhL.103d1603W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApPhL.103d1603W"><span id="translatedtitle">The effect of <span class="hlt">electron</span> induced hydrogenation of graphene on its electrical <span class="hlt">transport</span> properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Woo, Sung Oh; Teizer, Winfried</p> <p>2013-07-01</p> <p>We report a deterioration of the electrical <span class="hlt">transport</span> properties of a graphene field effect transistor due to energetic <span class="hlt">electron</span> irradiation on a stack of Poly Methyl Methacrylate (PMMA) on graphene (PMMA/graphene bilayer). Prior to <span class="hlt">electron</span> irradiation, we observed that the PMMA layer on graphene does not deteriorate the carrier <span class="hlt">transport</span> of graphene but improves its electrical properties instead. As a result of the <span class="hlt">electron</span> irradiation on the PMMA/graphene bilayer, the Raman "D" band appears after removal of PMMA. We argue that the degradation of the <span class="hlt">transport</span> behavior originates from the binding of hydrogen generated during the PMMA backbone secession process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MPLB...2750175L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MPLB...2750175L"><span id="translatedtitle">The <span class="hlt">Electron</span> <span class="hlt">Transport</span> in a Nanostructure Modulated by the Magnetic Field and the δ-DOPING</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Jian-Duo; Xu, Bin; Zheng, Wei</p> <p>2013-09-01</p> <p>We theoretically investigate the effect of the δ-doping on the <span class="hlt">electron</span> <span class="hlt">transport</span> in a magnetic nanostructure, which can be experimentally realized by depositing one ferromagnetic stripe on the top of a semiconductor heterostructure. We find that the position and the strength of the δ-doping as well as the distance between the two magnetic fields play an important role on the <span class="hlt">electron</span> <span class="hlt">transport</span> properties such as the transmission probability, the conductance and the spin polarization. These interesting results may be very helpful for analyzing the spin-dependent <span class="hlt">transport</span> mechanism of the <span class="hlt">electron</span> and making the new types of the spintronic devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApJ...728..133T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApJ...728..133T"><span id="translatedtitle">What Causes Scatter-free <span class="hlt">Transport</span> of Non-relativistic Solar <span class="hlt">Electrons</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, Lun C.; Reames, Donald V.; Ng, Chee K.; Shao, Xi; Wang, Linghua</p> <p>2011-02-01</p> <p>We have examined the cause of the scatter-free <span class="hlt">transport</span> of non-relativistic solar <span class="hlt">electrons</span>. <span class="hlt">Electron</span> scatter-free <span class="hlt">transport</span> events are compared with the diffusive <span class="hlt">transport</span> event. The emphasis of our examination is on the energy dependence of <span class="hlt">electron</span> angular distributions and the steepening of interplanetary magnetic field (IMF) power spectral densities (PSDs). Near and above the proton gyrofrequency, the effects of both R-mode (whistler) and L-mode (electromagnetic ion cyclotron, EMIC) waves need to be taken into account separately. The PSD spectral steepening due to the EMIC wave damping by solar-wind thermal ions becomes essential. In a fast-rise-fast-decay impulsive <span class="hlt">electron</span> event we have observed such steepening, which significantly reduces PSD levels at frequencies above the proton gyrofrequency. The spectral steepening thus produced favors the occurrence of scatter-free <span class="hlt">transport</span> of low-energy <span class="hlt">electrons</span>. Consequently, within the Wind/3D Plasma and Energetic Particle Instrument/Silicon Semiconductor Telescope measured energy range (~25-500 keV), there appears to be an <span class="hlt">electron</span> energy window, across which the scatter-free <span class="hlt">transport</span> of lower energy <span class="hlt">electrons</span> would change to the diffusive <span class="hlt">transport</span> of higher energy <span class="hlt">electrons</span>. We have observed such a change and found it is correlated with the occurrence of broken power-law spectra of <span class="hlt">electrons</span>. Thus the connection between the transition from diffusive to scatter-free <span class="hlt">electron</span> <span class="hlt">transport</span> and the concurrent transition from high to low IMF PSD levels with corresponding breaks in the <span class="hlt">electron</span> power-law energy spectrum and PSD spectrum has been recognized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CoPhC.203..268R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CoPhC.203..268R"><span id="translatedtitle">METHES: A Monte Carlo collision code for the simulation of <span class="hlt">electron</span> <span class="hlt">transport</span> in low temperature plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rabie, M.; Franck, C. M.</p> <p>2016-06-01</p> <p>We present a freely available MATLAB code for the simulation of <span class="hlt">electron</span> <span class="hlt">transport</span> in arbitrary gas mixtures in the presence of uniform electric fields. For steady-state <span class="hlt">electron</span> <span class="hlt">transport</span>, the program provides the <span class="hlt">transport</span> coefficients, reaction rates and the <span class="hlt">electron</span> energy distribution function. The program uses established Monte Carlo techniques and is compatible with the <span class="hlt">electron</span> scattering cross section files from the open-access Plasma Data Exchange Project LXCat. The code is written in object-oriented design, allowing the tracing and visualization of the spatiotemporal evolution of <span class="hlt">electron</span> swarms and the temporal development of the mean energy and the <span class="hlt">electron</span> number due to attachment and/or ionization processes. We benchmark our code with well-known model gases as well as the real gases argon, N2, O2, CF4, SF6 and mixtures of N2 and O2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38..714A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38..714A"><span id="translatedtitle">Complex role of secondary <span class="hlt">electron</span> emissions in dust grain charging in space <span class="hlt">environments</span>: measurements on Apollo 11 & 17 dust grains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abbas, Mian; Tankosic, Dragana; Spann, James; Leclair, Andre C.</p> <p></p> <p>Dust grains in various astrophysical <span class="hlt">environments</span> are generally charged electrostatically by photoelectric emissions with radiation from nearby sources, by <span class="hlt">electron</span>/ion collisions, and sec-ondary <span class="hlt">electron</span> emissions. Knowledge of the dust grain charges and equilibrium potentials is important for understanding of a variety of physical and dynamical processes in the interstel-lar medium (ISM), and heliospheric, interplanetary, planetary, and lunar <span class="hlt">environments</span>. The high vacuum <span class="hlt">environment</span> on the lunar surface leads to some unusual physical and dynam-ical phenomena involving dust grains with high adhesive characteristics, and levitation and <span class="hlt">transportation</span> over long distances. It has been well recognized that the charging properties of individual micron/submicron size dust grains are expected to be substantially different from the corresponding values for bulk materials and theoretical models. In this paper we present experimental results on charging of individual dust grains selected from Apollo 11 and Apollo 17 dust samples by exposing them to mono-energetic <span class="hlt">electron</span> beams in the 10-400 eV energy range. The charging rates of positively and negatively charged particles of 0.2 to 13 µm diam-eters are discussed in terms of the secondary <span class="hlt">electron</span> emission (SEE) process, which is found to be a complex charging process at <span class="hlt">electron</span> energies as low as 10-25 eV, with strong parti-cle size dependence. The measurements indicate substantial differences between dust charging properties of individual small size dust grains and of bulk materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/367109','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/367109"><span id="translatedtitle"><span class="hlt">Electron</span> ripple injection concept for tokamak <span class="hlt">transport</span> control</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Choe, W.; Ono, M.; Chang, C.S.</p> <p>1996-02-01</p> <p>A non-intrusive method for inducing a radial electric field ({ital E}{sub {ital r}}) based on <span class="hlt">electron</span> ripple injection (ERI) is under development by the Princeton CDX-U group. Since {ital E}{sub {ital r}} is known to play an important role in the L-H and H-VH mode transition, it is therefore important to develop a non-intrusive tool to control the {ital E}{sub {ital r}} profile in tokamak plasmas. The present technique utilizes externally-applied local magnetic ripple fields to trap <span class="hlt">electrons</span> at the edge, allowing them to penetrate towards the plasma center via {nabla}{ital B} and curvature drifts, causing the flux surfaces to charge up negatively. <span class="hlt">Electron</span> cyclotron resonance heating (ECRH) is utilized to increase the trapped population and the <span class="hlt">electron</span> drift velocity by raising the perpendicular energy of trapped <span class="hlt">electrons</span>. The temperature anisotropy of resonant <span class="hlt">electrons</span> in a tokamak plasma is calculated in order to investigate effects of ECRH on <span class="hlt">electrons</span>. Simulations using a guiding-center orbit model have been performed to understand the behavior of suprathermal <span class="hlt">electrons</span> in the presence of ripple fields. Examples for CDX-U and ITER are given. {copyright} {ital 1996 American Institute of Physics.}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23030098','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23030098"><span id="translatedtitle">Ambipolar <span class="hlt">transport</span> via trapped-<span class="hlt">electron</span> whistler instability along open magnetic field lines.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Zehua; Tang, Xian-Zhu</p> <p>2012-09-28</p> <p>An open field line plasma is bounded by a chamber wall which intercepts the magnetic field. Steady state requires an upstream plasma source balancing the particle loss to the boundary. In cases where the <span class="hlt">electrons</span> have a long mean free path, ambipolarity in parallel <span class="hlt">transport</span> critically depends on collisionless detrapping of the <span class="hlt">electrons</span> via wave-particle interaction. The trapped-<span class="hlt">electron</span> whistler instability, whose nonlinear saturation produces a spectrum of whistler waves that is responsible for the <span class="hlt">electron</span> detrapping flux, is shown to be an unusually robust kinetic instability, which is essential to the universality of the ambipolar constraint in plasma <span class="hlt">transport</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004PPCF...46A..71I&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004PPCF...46A..71I&link_type=ABSTRACT"><span id="translatedtitle">Cold pulse experiments in plasma with an <span class="hlt">electron</span> internal <span class="hlt">transport</span> barrier on LHD</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Inagaki, S.; Ida, K.; Tamura, N.; Shimozuma, T.; Kubo, S.; Nagayama, Y.; Kawahata, K.; Sudo, S.; Ohkubo, K.; LHD Experimental Group</p> <p>2004-05-01</p> <p>Transient <span class="hlt">transport</span> experiments are performed in LHD plasma with <span class="hlt">electron</span> internal <span class="hlt">transport</span> barrier (e-ITB). Evidence for a reduction of <span class="hlt">electron</span> heat diffusivity inside the ITB is observed from cold and heat pulse propagations. The observed enhancement of the cold pulse peak is explained by the temperature dependent <span class="hlt">electron</span> heat diffusivity. The heat diffusivity inside the ITB decreases with an increase in the <span class="hlt">electron</span> temperature in LHD. A preliminary version of this study was presented in the 29th EPS Conf. on Plasma Phys. and Control. Fusion (Montreux, Switzerland, 17 21 June 2002) [1].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20698372','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20698372"><span id="translatedtitle">Effect of <span class="hlt">electron</span> collisions on <span class="hlt">transport</span> coefficients induced by the inverse bremsstrahlung absorption in plasmas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bendib, A.; Tahraoui, A.; Bendib, K.; Mohammed El Hadj, K.; Hueller, S.</p> <p>2005-03-01</p> <p>The <span class="hlt">transport</span> coefficients of fully ionized plasmas under the influence of a high-frequency electric field are derived solving numerically the <span class="hlt">electron</span> Fokker-Planck equation using a perturbation method, parametrized as a function of the <span class="hlt">electron</span> mean-free-path {lambda}{sub ei} compared to the spatial scales L. The isotropic and anisotropic contributions of the inverse bremsstrahlung heating are considered. <span class="hlt">Electron-electron</span> collision terms are kept in the analysis, which allows us to consider with sufficient accuracy to describe plasmas with arbitrary atomic number Z. Practical numerical fits of the <span class="hlt">transport</span> coefficients are proposed as functions of Z and the collisionality parameter {lambda}{sub ei}/L.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......352S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......352S"><span id="translatedtitle"><span class="hlt">Electronic</span> structure and quantum <span class="hlt">transport</span> properties of metallic and semiconducting nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Simbeck, Adam J.</p> <p></p> <p>The future of the semiconductor industry hinges upon new developments to combat the scaling issues that currently afflict two main chip components: transistors and interconnects. For transistors this means investigating suitable materials to replace silicon for both the insulating gate and the semiconducting channel in order to maintain device performance with decreasing size. For interconnects this equates to overcoming the challenges associated with copper when the wire dimensions approach the confinement limit, as well as continuing to develop low-k dielectric materials that can assure minimal cross-talk between lines. In addition, such challenges make it increasingly clear that device design must move from a top-down to a bottom-up approach in which the desired <span class="hlt">electronic</span> characteristics are tailored from first-principles. It is with such fundamental hurdles in mind that ab initio calculations on the <span class="hlt">electronic</span> and quantum <span class="hlt">transport</span> properties of nanoscale metallic and semiconducting wires have been performed. More specifically, this study seeks to elaborate on the role played by confinement, contacts, dielectric <span class="hlt">environment</span>, edge decoration, and defects in altering the <span class="hlt">electronic</span> and <span class="hlt">transport</span> characteristics of such systems. As experiments continue to achieve better control over the synthesis and design of nanowires, these results are expected to become increasingly more important for not only the interpretation of <span class="hlt">electronic</span> and <span class="hlt">transport</span> trends, but also in engineering the <span class="hlt">electronic</span> structure of nanowires for the needs of the devices of the future. For the metallic atomic wires, the quantum <span class="hlt">transport</span> properties are first investigated by considering finite, single-atom chains of aluminum, copper, gold, and silver sandwiched between gold contacts. Non-equilibrium Green's function based <span class="hlt">transport</span> calculations reveal that even in the presence of the contact the conductivity of atomic-scale aluminum is greater than that of the other metals considered. This is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/574650','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/574650"><span id="translatedtitle"><span class="hlt">Electron</span> energy <span class="hlt">transport</span> in the solar wind: Ulysses observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Scime, E.E.; Gary, S.P.; Phillips, J.L.; Balogh, A.; Lengyel-Frey, D.</p> <p>1996-07-01</p> <p>Previous analysis suggests that the whistler heat flux instability is responsible for the regulation of the <span class="hlt">electron</span> heat flux of the solar wind. For an interval of quiescent solar wind during the in-ecliptic phase of the Ulysses mission, the plasma wave data in the whistler frequency regime are compared to the predictions of the whistler heat flux instability model. The data is well constrained by the predicted upper bound on the <span class="hlt">electron</span> heat flux and a clear correlation between wave activity and <span class="hlt">electron</span> heat flux dissipation is observed. {copyright} {ital 1996 American Institute of Physics.}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21163474','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21163474"><span id="translatedtitle"><span class="hlt">Electron</span> energy <span class="hlt">transport</span> in the solar wind: Ulysses observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Scime, Earl E.; Gary, S. Peter; Phillips, John L.; Balogh, Andre; Lengyel-Frey, Denise</p> <p>1996-07-20</p> <p>Previous analysis suggests that the whistler heat flux instability is responsible for the regulation of the <span class="hlt">electron</span> heat flux of the solar wind. For an interval of quiescent solar wind during the in-ecliptic phase of the Ulysses mission, the plasma wave data in the whistler frequency regime are compared to the predictions of the whistler heat flux instability model. The data is well constrained by the predicted upper bound on the <span class="hlt">electron</span> heat flux and a clear correlation between wave activity and <span class="hlt">electron</span> heat flux dissipation is observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AnGeo..27.2173U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AnGeo..27.2173U"><span id="translatedtitle">Radial <span class="hlt">transport</span> of radiation belt <span class="hlt">electrons</span> due to stormtime Pc5 waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ukhorskiy, A. Y.; Sitnov, M. I.; Takahashi, K.; Anderson, B. J.</p> <p>2009-05-01</p> <p>During geomagnetic storms relativistic <span class="hlt">electron</span> fluxes in the outer radiation belt exhibit dynamic variability over multiple orders of magnitude. This requires radial <span class="hlt">transport</span> of <span class="hlt">electrons</span> across their drift shells and implies violation of their third adiabatic invariant. Radial <span class="hlt">transport</span> is induced by the interaction of the <span class="hlt">electron</span> drift motion with electric and magnetic field fluctuations in the ULF frequency range. It was previously shown that solar-wind driven ULF waves have long azimuthal wave lengths and thus can violate the third invariant of trapped <span class="hlt">electrons</span> in the process of resonant interaction with their gradient-curvature motion. However, the amplitude of solar-wind driven ULF waves rapidly decreases with decreasing L. It is therefore not clear what mechanisms are responsible for fast <span class="hlt">transport</span> rates observed inside the geosynchronous orbit. In this paper we investigate wether stormtime Pc5 waves can contribute to this process. Stormtime Pc5s have short azimuthal wave lengths and therefore cannot exhibit resonance with the the <span class="hlt">electron</span> drift motion. However we show that stormtime Pc5s can cause localized random scattering of <span class="hlt">electron</span> drift motion that violates the third invariant. According to our results <span class="hlt">electron</span> interaction with stormtime Pc5s can produce rapid radial <span class="hlt">transport</span> even as low as L≃4. Numerical simulations show that <span class="hlt">electron</span> <span class="hlt">transport</span> can exhibit large deviations from radial diffusion. The diffusion approximation is not valid for individual storms but only applies to the statistically averaged response of the outer belt to stormtime Pc5 waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title41-vol3/pdf/CFR-2010-title41-vol3-sec102-118-80.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title41-vol3/pdf/CFR-2010-title41-vol3-sec102-118-80.pdf"><span id="translatedtitle">41 CFR 102-118.80 - Who is responsible for keeping my agency's <span class="hlt">electronic</span> commerce <span class="hlt">transportation</span> billing records?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... keeping my agency's <span class="hlt">electronic</span> commerce <span class="hlt">transportation</span> billing records? 102-118.80 Section 102-118.80... <span class="hlt">Transportation</span> and <span class="hlt">Transportation</span> Services § 102-118.80 Who is responsible for keeping my agency's <span class="hlt">electronic</span> commerce <span class="hlt">transportation</span> billing records? Your agency's internal financial regulations will...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JCHyd.164..125H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JCHyd.164..125H"><span id="translatedtitle">Measurement and modeling of phosphorous <span class="hlt">transport</span> in shallow groundwater <span class="hlt">environments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hendricks, G. S.; Shukla, S.; Obreza, T. A.; Harris, W. G.</p> <p>2014-08-01</p> <p>Leaching of phosphorus (P) from agricultural soils, especially those that are sandy, is adversely impacting P-limited ecosystems like Florida's Everglades. A more developed understanding of P and water management strategies and their effects on P leaching is needed to achieve reductions in subsurface P losses, especially from intensively managed dual cropping systems under plastic mulch in shallow water regions. We compared the effects of conservation P and water management strategies with traditional practices on P <span class="hlt">transport</span> to groundwater. A 3-year experiment was conducted on hydrologically isolated plots with plastic-mulched successive cropping systems to compare high (HEI) and soil test based recommended (REI) external input (water and fertilizer P) systems with traditional sub-irrigation (seepage), and REI with a potential water conservation subsurface drip irrigation system (REI-SD) with regard to groundwater P concentrations above and below the low conductivity spodic horizon (Bh). The REI treatments had higher available storage for rainfall and P than HEI. Use of both REI systems (REI = 2098 μg/L and REI-SD = 2048 μg/L) reduced groundwater P concentrations above the Bh horizon by 33% compared to HEI (3090 μg/L), and results were significant at the 0.05 level. Although the subsurface drip system saved water, it did not offer any groundwater quality (P) benefit. Mixing and dilution of influent P below the low conductivity Bh horizon between treatments and with the regional groundwater system resulted in no significant differences in groundwater P concentration below the Bh horizon. Groundwater P concentrations from this study were higher than reported elsewhere due to low soil P storage capacity (SPSC), high hydraulic conductivity of sandy soils, and a high water table beneath crop beds. The HEI system leached more P due to ferilizer P in excess of SPSC and used higher irrigation volumes compared with REI systems. Despite a 40% difference in the average</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24981965','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24981965"><span id="translatedtitle">Measurement and modeling of phosphorous <span class="hlt">transport</span> in shallow groundwater <span class="hlt">environments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hendricks, G S; Shukla, S; Obreza, T A; Harris, W G</p> <p>2014-08-01</p> <p>Leaching of phosphorus (P) from agricultural soils, especially those that are sandy, is adversely impacting P-limited ecosystems like Florida's Everglades. A more developed understanding of P and water management strategies and their effects on P leaching is needed to achieve reductions in subsurface P losses, especially from intensively managed dual cropping systems under plastic mulch in shallow water regions. We compared the effects of conservation P and water management strategies with traditional practices on P <span class="hlt">transport</span> to groundwater. A 3-year experiment was conducted on hydrologically isolated plots with plastic-mulched successive cropping systems to compare high (HEI) and soil test based recommended (REI) external input (water and fertilizer P) systems with traditional sub-irrigation (seepage), and REI with a potential water conservation subsurface drip irrigation system (REI-SD) with regard to groundwater P concentrations above and below the low conductivity spodic horizon (Bh). The REI treatments had higher available storage for rainfall and P than HEI. Use of both REI systems (REI=2098μg/L and REI-SD=2048μg/L) reduced groundwater P concentrations above the Bh horizon by 33% compared to HEI (3090μg/L), and results were significant at the 0.05 level. Although the subsurface drip system saved water, it did not offer any groundwater quality (P) benefit. Mixing and dilution of influent P below the low conductivity Bh horizon between treatments and with the regional groundwater system resulted in no significant differences in groundwater P concentration below the Bh horizon. Groundwater P concentrations from this study were higher than reported elsewhere due to low soil P storage capacity (SPSC), high hydraulic conductivity of sandy soils, and a high water table beneath crop beds. The HEI system leached more P due to ferilizer P in excess of SPSC and used higher irrigation volumes compared with REI systems. Despite a 40% difference in the average amount of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24981965','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24981965"><span id="translatedtitle">Measurement and modeling of phosphorous <span class="hlt">transport</span> in shallow groundwater <span class="hlt">environments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hendricks, G S; Shukla, S; Obreza, T A; Harris, W G</p> <p>2014-08-01</p> <p>Leaching of phosphorus (P) from agricultural soils, especially those that are sandy, is adversely impacting P-limited ecosystems like Florida's Everglades. A more developed understanding of P and water management strategies and their effects on P leaching is needed to achieve reductions in subsurface P losses, especially from intensively managed dual cropping systems under plastic mulch in shallow water regions. We compared the effects of conservation P and water management strategies with traditional practices on P <span class="hlt">transport</span> to groundwater. A 3-year experiment was conducted on hydrologically isolated plots with plastic-mulched successive cropping systems to compare high (HEI) and soil test based recommended (REI) external input (water and fertilizer P) systems with traditional sub-irrigation (seepage), and REI with a potential water conservation subsurface drip irrigation system (REI-SD) with regard to groundwater P concentrations above and below the low conductivity spodic horizon (Bh). The REI treatments had higher available storage for rainfall and P than HEI. Use of both REI systems (REI=2098μg/L and REI-SD=2048μg/L) reduced groundwater P concentrations above the Bh horizon by 33% compared to HEI (3090μg/L), and results were significant at the 0.05 level. Although the subsurface drip system saved water, it did not offer any groundwater quality (P) benefit. Mixing and dilution of influent P below the low conductivity Bh horizon between treatments and with the regional groundwater system resulted in no significant differences in groundwater P concentration below the Bh horizon. Groundwater P concentrations from this study were higher than reported elsewhere due to low soil P storage capacity (SPSC), high hydraulic conductivity of sandy soils, and a high water table beneath crop beds. The HEI system leached more P due to ferilizer P in excess of SPSC and used higher irrigation volumes compared with REI systems. Despite a 40% difference in the average amount of</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAP...117x5503W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAP...117x5503W"><span id="translatedtitle">Color stable white phosphorescent organic light emitting diodes with red emissive <span class="hlt">electron</span> <span class="hlt">transport</span> layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wook Kim, Jin; Yoo, Seung Il; Sung Kang, Jin; Eun Lee, Song; Kwan Kim, Young; Hwa Yu, Hyeong; Turak, Ayse; Young Kim, Woo</p> <p>2015-06-01</p> <p>We analyzed the performance of multi-emissive white phosphorescent organic light-emitting diodes (PHOLEDs) in relation to various red emitting sites of hole and <span class="hlt">electron</span> <span class="hlt">transport</span> layers (HTL and ETL). The shift of the recombination zone producing stable white emission in PHOLEDs was utilized as luminance was increased with red emission in its <span class="hlt">electron</span> <span class="hlt">transport</span> layer. Multi-emissive white PHOLEDs including the red light emitting <span class="hlt">electron</span> <span class="hlt">transport</span> layer yielded maximum external quantum efficiency of 17.4% with CIE color coordinates (-0.030, +0.001) shifting only from 1000 to 10 000 cd/m2. Additionally, we observed a reduction of energy loss in the white PHOLED via Ir(piq)3 as phosphorescent red dopant in <span class="hlt">electron</span> <span class="hlt">transport</span> layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23176467','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23176467"><span id="translatedtitle">A long way to the electrode: how do Geobacter cells <span class="hlt">transport</span> their <span class="hlt">electrons</span>?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bonanni, Pablo Sebastián; Schrott, Germán David; Busalmen, Juan Pablo</p> <p>2012-12-01</p> <p>The mechanism of <span class="hlt">electron</span> <span class="hlt">transport</span> in Geobacter sulfurreducens biofilms is a topic under intense study and debate. Although some proteins were found to be essential for current production, the specific role that each one plays in <span class="hlt">electron</span> <span class="hlt">transport</span> to the electrode remains to be elucidated and a consensus on the mechanism of <span class="hlt">electron</span> <span class="hlt">transport</span> has not been reached. In the present paper, to understand the state of the art in the topic, <span class="hlt">electron</span> <span class="hlt">transport</span> from inside of the cell to the electrode in Geobacter sulfurreducens biofilms is analysed, reviewing genetic studies, biofilm conductivity assays and electrochemical and spectro-electrochemical experiments. Furthermore, crucial data still required to achieve a deeper understanding are highlighted. PMID:23176467</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22490743','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22490743"><span id="translatedtitle">Color stable white phosphorescent organic light emitting diodes with red emissive <span class="hlt">electron</span> <span class="hlt">transport</span> layer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wook Kim, Jin; Yoo, Seung Il; Sung Kang, Jin; Eun Lee, Song; Kwan Kim, Young; Hwa Yu, Hyeong; Turak, Ayse; Young Kim, Woo</p> <p>2015-06-28</p> <p>We analyzed the performance of multi-emissive white phosphorescent organic light-emitting diodes (PHOLEDs) in relation to various red emitting sites of hole and <span class="hlt">electron</span> <span class="hlt">transport</span> layers (HTL and ETL). The shift of the recombination zone producing stable white emission in PHOLEDs was utilized as luminance was increased with red emission in its <span class="hlt">electron</span> <span class="hlt">transport</span> layer. Multi-emissive white PHOLEDs including the red light emitting <span class="hlt">electron</span> <span class="hlt">transport</span> layer yielded maximum external quantum efficiency of 17.4% with CIE color coordinates (−0.030, +0.001) shifting only from 1000 to 10 000 cd/m{sup 2}. Additionally, we observed a reduction of energy loss in the white PHOLED via Ir(piq){sub 3} as phosphorescent red dopant in <span class="hlt">electron</span> <span class="hlt">transport</span> layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1206544','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1206544"><span id="translatedtitle">Ultrafast <span class="hlt">electron</span> <span class="hlt">transport</span> across nano gaps in nanowire circuits</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Potma, Eric O.</p> <p>2015-07-31</p> <p>In this Program we aim for a closer look at <span class="hlt">electron</span> transfer through single molecules. To achieve this, we use ultrafast laser pulses to time stamp an <span class="hlt">electron</span> tunneling event in a molecule that is connected between two metallic electrodes, while reading out the <span class="hlt">electron</span> current. A key aspect of this project is the use of metallic substrates with plasmonic activity to efficiently manipulate the tunneling probability. The first Phase of this program is concerned with developing highly sensitive tools for the ultrafast optical manipulation of tethered molecules through the evanescent surface field of plasmonic substrates. The second Phase of the program aims to use these tools for exercising control over the <span class="hlt">electron</span> tunneling probability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=multivariate+AND+random+AND+model&pg=2&id=EJ1051934','ERIC'); return false;" href="http://eric.ed.gov/?q=multivariate+AND+random+AND+model&pg=2&id=EJ1051934"><span id="translatedtitle">Modeling Growth in <span class="hlt">Electronic</span> Learning <span class="hlt">Environments</span> Using a Longitudinal Random Item Response Model</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kadengye, Damazo T.; Ceulemans, Eva; Van Den Noortgate, Wim</p> <p>2015-01-01</p> <p>In educational <span class="hlt">environments</span>, monitoring persons' progress over time may help teachers to evaluate the effectiveness of their teaching procedures. <span class="hlt">Electronic</span> learning <span class="hlt">environments</span> are increasingly being used as part of formal education and resulting datasets can be used to understand and to improve the <span class="hlt">environment</span>. This study presents…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1061446','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1061446"><span id="translatedtitle"><span class="hlt">Electron</span> Beam <span class="hlt">Transport</span> in Advanced Plasma Wave Accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Williams, Ronald L</p> <p>2013-01-31</p> <p>The primary goal of this grant was to develop a diagnostic for relativistic plasma wave accelerators based on injecting a low energy <span class="hlt">electron</span> beam (5-50keV) perpendicular to the plasma wave and observing the distortion of the <span class="hlt">electron</span> beam's cross section due to the plasma wave's electrostatic fields. The amount of distortion would be proportional to the plasma wave amplitude, and is the basis for the diagnostic. The beat-wave scheme for producing plasma waves, using two CO2 laser beam, was modeled using a leap-frog integration scheme to solve the equations of motion. Single <span class="hlt">electron</span> trajectories and corresponding phase space diagrams were generated in order to study and understand the details of the interaction dynamics. The <span class="hlt">electron</span> beam was simulated by combining thousands of single <span class="hlt">electrons</span>, whose initial positions and momenta were selected by random number generators. The model was extended by including the interactions of the <span class="hlt">electrons</span> with the CO2 laser fields of the beat wave, superimposed with the plasma wave fields. The results of the model were used to guide the design and construction of a small laboratory experiment that may be used to test the diagnostic idea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JPSCP...1a6012E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPSCP...1a6012E"><span id="translatedtitle">First-Principles Study on Dynamic <span class="hlt">Electron-Transport</span> Property through Low Dimensional System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Egami, Yoshiyuki; Hirose, Kikuji</p> <p></p> <p>We present an investigation of <span class="hlt">electron-transport</span> in a low-dimensional system using a time-dependent first-principles simulator. The response time for the peaks in the transmission curve of a molecular chain system is discussed. Two types of resonant-tunneling channels with different responses to changes in the conformation are observed. It is found that one of the channels plays a minor role in the contribution to the <span class="hlt">electron</span> <span class="hlt">transport</span> because of its poor response.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/828197','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/828197"><span id="translatedtitle"><span class="hlt">Electron</span> Cross-field <span class="hlt">Transport</span> in a Low Power Cylindrical Hall Thruster</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>A. Smirnov; Y. Raitses; N.J. Fisch</p> <p>2004-06-24</p> <p>Conventional annular Hall thrusters become inefficient when scaled to low power. Cylindrical Hall thrusters, which have lower surface-to-volume ratio, are therefore more promising for scaling down. They presently exhibit performance comparable with conventional annular Hall thrusters. <span class="hlt">Electron</span> cross-field <span class="hlt">transport</span> in a 2.6 cm miniaturized cylindrical Hall thruster (100 W power level) has been studied through the analysis of experimental data and Monte Carlo simulations of <span class="hlt">electron</span> dynamics in the thruster channel. The numerical model takes into account elastic and inelastic <span class="hlt">electron</span> collisions with atoms, <span class="hlt">electron</span>-wall collisions, including secondary <span class="hlt">electron</span> emission, and Bohm diffusion. We show that in order to explain the observed discharge current, the <span class="hlt">electron</span> anomalous collision frequency {nu}{sub B} has to be on the order of the Bohm value, {nu}{sub B} {approx} {omega}{sub c}/16. The contribution of <span class="hlt">electron</span>-wall collisions to cross-field <span class="hlt">transport</span> is found to be insignificant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21376011','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21376011"><span id="translatedtitle">Alternative photosynthetic <span class="hlt">electron</span> <span class="hlt">transport</span> pathways during anaerobiosis in the green alga Chlamydomonas reinhardtii.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hemschemeier, Anja; Happe, Thomas</p> <p>2011-08-01</p> <p>Oxygenic photosynthesis uses light as energy source to generate an oxidant powerful enough to oxidize water into oxygen, <span class="hlt">electrons</span> and protons. Upon linear <span class="hlt">electron</span> <span class="hlt">transport</span>, <span class="hlt">electrons</span> extracted from water are used to reduce NADP(+) to NADPH. The oxygen molecule has been integrated into the cellular metabolism, both as the most efficient <span class="hlt">electron</span> acceptor during respiratory <span class="hlt">electron</span> <span class="hlt">transport</span> and as oxidant and/or "substrate" in a number of biosynthetic pathways. Though photosynthesis of higher plants, algae and cyanobacteria produces oxygen, there are conditions under which this type of photosynthesis operates under hypoxic or anaerobic conditions. In the unicellular green alga Chlamydomonas reinhardtii, this condition is induced by sulfur deficiency, and it results in the production of molecular hydrogen. Research on this biotechnologically relevant phenomenon has contributed largely to new insights into additional pathways of photosynthetic <span class="hlt">electron</span> <span class="hlt">transport</span>, which extend the former concept of linear <span class="hlt">electron</span> flow by far. This review summarizes the recent knowledge about various <span class="hlt">electron</span> sources and sinks of oxygenic photosynthesis besides water and NADP(+) in the context of their contribution to hydrogen photoproduction by C. reinhardtii. This article is part of a Special Issue entitled: Regulation of <span class="hlt">Electron</span> <span class="hlt">Transport</span> in Chloroplasts. PMID:21376011</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2012-08-09/pdf/2012-19584.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2012-08-09/pdf/2012-19584.pdf"><span id="translatedtitle">77 FR 47692 - Notice of <span class="hlt">Transportation</span> Services' Transition From Paper to <span class="hlt">Electronic</span> Fare Media Comments...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2012-08-09</p> <p>... Office of the Secretary of <span class="hlt">Transportation</span> Notice of <span class="hlt">Transportation</span> Services' Transition From Paper to... transitioning, or have already transitioned, to <span class="hlt">electronic</span> fare media, compelling the shift from a paper based... participating Federal employees via a paper voucher process. In addition to a growing number of...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1054624','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1054624"><span id="translatedtitle">Hormone Action on Transmembrane <span class="hlt">Electron</span> and H+ <span class="hlt">Transport</span> 1</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Böttger, Michael; Hilgendorf, Frank</p> <p>1988-01-01</p> <p>A possible involvement of two different systems in proton translocation was investigated by simultaneous measurement of transmembrane <span class="hlt">electron</span> flow and proton secretion in a pH-stat combined with a redoxstat. The pH gradient between cytoplasm and apoplast is probably maintained by an H+ -pumping ATPase and by a second proton extrusion system, which seems to be linked to a redox chain with NAD(P)H as <span class="hlt">electron</span> donor. Indole acetic acid inhibits both e− and H+ efflux, but only if the `<span class="hlt">electron</span> draw' from the outside is not too high. The <span class="hlt">electron</span> draw depends on the hexacyanoferrate level at the plasmalemma surface and on the Ca2+ concentration. The inhibiting effect of auxin on e− and H+ efflux in the presence of hexacyanoferrate can be only detected at low levels of bivalent cations and of the artificial <span class="hlt">electron</span> acceptor. The inhibition of e− and H+ efflux by auxin requires high oxygen levels. The influence of auxin on both e− and H+ transfer disappears below 2 kilopascals O2, a level which does not influence respiration. Ethanol and fusicoccin do not increase the e− flux, probably because the <span class="hlt">electron</span> transfer from the plasma membrane to HCF III is the limiting step. If <span class="hlt">electron</span> transfer is reduced by IAA pretreatment, ethanol increases e− flux. Fusicoccin decreases e− and increases H+ efflux if the rates have been lowered previously by indole acetic acid pretreatment. This effect depends on high oxygen levels and is reversible by lowering oxygen pressure. Auxin and Ca2+ change e− flow and H+ ejection in a 1:1 ratio. PMID:16666028</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=mail+AND+electronic&pg=5&id=EJ631390','ERIC'); return false;" href="http://eric.ed.gov/?q=mail+AND+electronic&pg=5&id=EJ631390"><span id="translatedtitle">Exploring the Academic Self within an <span class="hlt">Electronic</span> Mail <span class="hlt">Environment</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Spires, Hiller A.; Mason, Cheryl; Crissman, Cris; Jackson, Alecia</p> <p>2001-01-01</p> <p>Reports on a study at North Carolina State University that examined the use of <span class="hlt">electronic</span> mail to encourage critical literacy among college developmental reading students. States that randomly selected students were paired with professionals who served as online mentors. Reports that, after one semester, this group scored higher than the control…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED421164.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED421164.pdf"><span id="translatedtitle">Replacing the Tin Can: Creating an Effective <span class="hlt">Electronic</span> Communication <span class="hlt">Environment</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Powers, Susan M.; Dutt-Doner, Karen M.</p> <p></p> <p><span class="hlt">Electronic</span> communication tools may have more in common with the old communication game where tin cans were connected by a string than with traditional classroom communication. The charge is to find ways to make the communication more like, and possibly better, than effective classroom communication. Creating a firm foundation for successful…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7028060','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/7028060"><span id="translatedtitle"><span class="hlt">Electronically</span> conductive ceramics for high temperature oxidizing <span class="hlt">environments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kucera, G.H.; Smith, J.L.; Sim, J.W.</p> <p>1983-11-10</p> <p>This invention pertains to a high temperature, ceramic composition having <span class="hlt">electronic</span> conductivity as measured by resistivity below about 500 ohm-cm, chemical stability particularly with respect to cathode conditions in a molten carbonate fuel cell, and composed of an alkali metal, transition metal oxide containing a dopant metal in the crystalline structure to replace a portion of the alkali metal or transition metal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/865739','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/865739"><span id="translatedtitle"><span class="hlt">Electronically</span> conductive ceramics for high temperature oxidizing <span class="hlt">environments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kucera, Gene H.; Smith, James L.; Sim, James W.</p> <p>1986-01-01</p> <p>A high temperature, ceramic composition having <span class="hlt">electronic</span> conductivity as measured by resistivity below about 500 ohm-cm, chemical stability particularly with respect to cathode conditions in a molten carbonate fuel cell, and composed of an alkali metal, transition metal oxide containing a dopant metal in the crystalline structure to replace a portion of the alkali metal or transition metal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060044324&hterms=behavoir&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbehavoir','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060044324&hterms=behavoir&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbehavoir"><span id="translatedtitle">Re-configurable <span class="hlt">electronics</span> behavoir under extreme thermal <span class="hlt">environment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stoica, Adrian; Lacayo, Veronica; Rajeshuni, Ramesham; Keymeulen, Didier; Zebulum, Ricardo; Neff, Joe; Burke, Gary; Daud, Taher</p> <p>2005-01-01</p> <p>This paper focuses on analog/digital <span class="hlt">electronics</span> at low-temperatures. The experiments cover separate tests of the whole Evolvable Hardware system: the Evolutionary Processor (the DSP in the SABLE system), Xilinx Virtes II Pro FPGA evaluation board, and the Reconfigurable analog array components tested at low and high temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10157761','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10157761"><span id="translatedtitle">System response of a DOE Defense Program package in a <span class="hlt">transportation</span> accident <span class="hlt">environment</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, T.F.; Hovingh, J.; Kimura, C.Y.</p> <p>1992-10-15</p> <p>The system response in a <span class="hlt">transportation</span> accident <span class="hlt">environment</span> is an element to be considered in an overall <span class="hlt">Transportation</span> System Risk Assessment (TSRA) framework. The system response analysis uses the accident conditions and the subsequent accident progression analysis to develop the accident source term, which in turn, is used in the consequence analysis. This paper proposes a methodology for the preparation of the system response aspect of the TSRA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Nanot..27z5706H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nanot..27z5706H"><span id="translatedtitle">Strain-modulated <span class="hlt">electronic</span> and thermal <span class="hlt">transport</span> properties of two-dimensional O-silica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Han, Yang; Qin, Guangzhao; Jungemann, Christoph; Hu, Ming</p> <p>2016-07-01</p> <p>Silica is one of the most abundant materials in the Earth’s crust and is a remarkably versatile and important engineering material in various modern science and technology. Recently, freestanding and well-ordered two-dimensional (2D) silica monolayers with octahedral (O-silica) building blocks were found to be theoretically stable by (Wang G et al 2015 J. Phys. Chem. C 119 15654-60). In this paper, by performing first-principles calculations, we systematically investigated the <span class="hlt">electronic</span> and thermal <span class="hlt">transport</span> properties of 2D O-silica and also studied how these properties can be tuned by simple mechanical stretching. Unstrained 2D O-silica is an insulator with an indirect band gap of 6.536 eV. The band gap decreases considerably with bilateral strain up to 29%, at which point a semiconductor-metal transition occurs. More importantly, the in-plane thermal conductivity of freestanding 2D O-silica is found to be unusually high, which is around 40 to 50 times higher than that of bulk α-quartz and more than two orders of magnitude higher than that of amorphous silica. The thermal conductivity of O-silica decreases by almost two orders of magnitude when the bilateral stretching strain reaches 10%. By analyzing the mode-dependent phonon properties and phonon-scattering channel, the phonon lifetime is found to be the dominant factor that leads to the dramatic decrease of the lattice thermal conductivity under strain. The very sensitive response of both band gap and phonon <span class="hlt">transport</span> properties to the external mechanical strain will enable 2D O-silica to easily adapt to the different <span class="hlt">environment</span> of realistic applications. Our study is expected to stimulate experimental exploration of further physical and chemical properties of 2D silica systems, and offers perspectives on modulating the <span class="hlt">electronic</span> and thermal properties of related low-dimensional structures for applications such as thermoelectric, photovoltaic, and optoelectronic devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27199352','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27199352"><span id="translatedtitle">Strain-modulated <span class="hlt">electronic</span> and thermal <span class="hlt">transport</span> properties of two-dimensional O-silica.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Han, Yang; Qin, Guangzhao; Jungemann, Christoph; Hu, Ming</p> <p>2016-07-01</p> <p>Silica is one of the most abundant materials in the Earth's crust and is a remarkably versatile and important engineering material in various modern science and technology. Recently, freestanding and well-ordered two-dimensional (2D) silica monolayers with octahedral (O-silica) building blocks were found to be theoretically stable by (Wang G et al 2015 J. Phys. Chem. C 119 15654-60). In this paper, by performing first-principles calculations, we systematically investigated the <span class="hlt">electronic</span> and thermal <span class="hlt">transport</span> properties of 2D O-silica and also studied how these properties can be tuned by simple mechanical stretching. Unstrained 2D O-silica is an insulator with an indirect band gap of 6.536 eV. The band gap decreases considerably with bilateral strain up to 29%, at which point a semiconductor-metal transition occurs. More importantly, the in-plane thermal conductivity of freestanding 2D O-silica is found to be unusually high, which is around 40 to 50 times higher than that of bulk α-quartz and more than two orders of magnitude higher than that of amorphous silica. The thermal conductivity of O-silica decreases by almost two orders of magnitude when the bilateral stretching strain reaches 10%. By analyzing the mode-dependent phonon properties and phonon-scattering channel, the phonon lifetime is found to be the dominant factor that leads to the dramatic decrease of the lattice thermal conductivity under strain. The very sensitive response of both band gap and phonon <span class="hlt">transport</span> properties to the external mechanical strain will enable 2D O-silica to easily adapt to the different <span class="hlt">environment</span> of realistic applications. Our study is expected to stimulate experimental exploration of further physical and chemical properties of 2D silica systems, and offers perspectives on modulating the <span class="hlt">electronic</span> and thermal properties of related low-dimensional structures for applications such as thermoelectric, photovoltaic, and optoelectronic devices. PMID:27199352</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Nanot..27z5706H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Nanot..27z5706H&link_type=ABSTRACT"><span id="translatedtitle">Strain-modulated <span class="hlt">electronic</span> and thermal <span class="hlt">transport</span> properties of two-dimensional O-silica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Han, Yang; Qin, Guangzhao; Jungemann, Christoph; Hu, Ming</p> <p>2016-07-01</p> <p>Silica is one of the most abundant materials in the Earth’s crust and is a remarkably versatile and important engineering material in various modern science and technology. Recently, freestanding and well-ordered two-dimensional (2D) silica monolayers with octahedral (O-silica) building blocks were found to be theoretically stable by (Wang G et al 2015 J. Phys. Chem. C 119 15654–60). In this paper, by performing first-principles calculations, we systematically investigated the <span class="hlt">electronic</span> and thermal <span class="hlt">transport</span> properties of 2D O-silica and also studied how these properties can be tuned by simple mechanical stretching. Unstrained 2D O-silica is an insulator with an indirect band gap of 6.536 eV. The band gap decreases considerably with bilateral strain up to 29%, at which point a semiconductor–metal transition occurs. More importantly, the in-plane thermal conductivity of freestanding 2D O-silica is found to be unusually high, which is around 40 to 50 times higher than that of bulk α-quartz and more than two orders of magnitude higher than that of amorphous silica. The thermal conductivity of O-silica decreases by almost two orders of magnitude when the bilateral stretching strain reaches 10%. By analyzing the mode-dependent phonon properties and phonon-scattering channel, the phonon lifetime is found to be the dominant factor that leads to the dramatic decrease of the lattice thermal conductivity under strain. The very sensitive response of both band gap and phonon <span class="hlt">transport</span> properties to the external mechanical strain will enable 2D O-silica to easily adapt to the different <span class="hlt">environment</span> of realistic applications. Our study is expected to stimulate experimental exploration of further physical and chemical properties of 2D silica systems, and offers perspectives on modulating the <span class="hlt">electronic</span> and thermal properties of related low-dimensional structures for applications such as thermoelectric, photovoltaic, and optoelectronic devices.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21403192','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21403192"><span id="translatedtitle">The effect of magnetic field and disorders on the <span class="hlt">electronic</span> <span class="hlt">transport</span> in graphene nanoribbons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kumar, S Bala; Jalil, M B A; Tan, S G; Liang, Gengchiau</p> <p>2010-09-22</p> <p>We developed a unified mesoscopic <span class="hlt">transport</span> model for graphene nanoribbons, which combines the nonequilibrium Green's function (NEGF) formalism with the real-space π-orbital model. Based on this model, we probe the spatial distribution of <span class="hlt">electrons</span> under a magnetic field, in order to obtain insights into the various signature Hall effects in disordered armchair graphene nanoribbons (AGNR). In the presence of a uniform perpendicular magnetic field (B[Symbol: see text]-field), a perfect AGNR shows three distinct spatial current profiles at equilibrium, depending on its width. Under nonequilibrium conditions (i.e. in the presence of an applied bias), the net <span class="hlt">electron</span> flow is restricted to the edges and occurs in opposite directions depending on whether the Fermi level lies within the valence or conduction band. For <span class="hlt">electrons</span> at an energy level below the conduction window, the B[Symbol: see text]-field gives rise to local <span class="hlt">electron</span> flux circulation, although the global flux is zero. Our study also reveals the suppression of <span class="hlt">electron</span> backscattering as a result of the edge <span class="hlt">transport</span> which is induced by the B[Symbol: see text]-field. This phenomenon can potentially mitigate the undesired effects of disorder, such as bulk and edge vacancies, on the <span class="hlt">transport</span> properties of AGNR. Lastly, we show that the effect of [Formula: see text]-field on <span class="hlt">electronic</span> <span class="hlt">transport</span> is less significant in the multimode compared to the single-mode <span class="hlt">electron</span> <span class="hlt">transport</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080020515','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080020515"><span id="translatedtitle">Lunar Dust Charging by Secondary <span class="hlt">Electron</span> Emission and its Complex Role in the Lunar <span class="hlt">Environment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Abbas, M. M.; Tankosic, D.; Spann, J. F.; LeClair, A.; Dube, M. J.</p> <p>2008-01-01</p> <p>The lunar surface is covered with a thick layer of micron/sub-micron size dust grains formed by billions of years of meteoritic impact. With virtually no atmosphere and exposed to the solar wind plasma and solar electromagnetic radiation, the lunar surface and the dust grains are electrostatically charged. The dominant charging processes include: photoelectric emissions (UV, X-rays), impact of solar wind <span class="hlt">electrons</span> and ions, and secondary <span class="hlt">electron</span> emissions (SEE) induced by energetic solar wind <span class="hlt">electrons</span>. During the Apollo missions, the astronauts found the lunar dust to be extraordinarily high in its adhesive characteristics, sticking to the suits and the mechanical equipment. Electrostatically charged lunar dust is believed to be <span class="hlt">transported</span> over long distances by the induced electric fields, as indicated by the observed dust streamers and the horizon glow [e.g., 1-3]. The hazardous effects of dust in the lunar <span class="hlt">environment</span> are recognized to be one of the major issues that must be addressed in planning the forthcoming missions for robotic and human exploration of the Moon. Theoretical studies are being performed along with the development of analytical models and a variety of experimental investigations, to better understand the lunar dust phenomena. [e.g., 4-6]. The lunar dust is believed to be charged negatively on the lunar night-side by interaction With solar wind <span class="hlt">electrons</span>. However, rigorous theoretical expressions for calculation of SEE yields and the sticking efficiencies of individual micron size dust grains are not yet available, and the information has to be obtained by experiment. On theoretical considerations, however, it is well recognized that SEE yields, similar to the photoelectric yields for small-size grains, would be totally different from the corresponding bulk values [e.g., 7-9]. Some theoretical models for charging of individual small spherical particles have been developed [e.g., 10], and some limited measurements on individual metallic dust</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21694120','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21694120"><span id="translatedtitle"><span class="hlt">Electronic</span>, magnetic and <span class="hlt">transport</span> properties of rare-earth monopnictides.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duan, Chun-Gang; Sabirianov, R F; Mei, W N; Dowben, P A; Jaswal, S S; Tsymbal, E Y</p> <p>2007-08-01</p> <p>The <span class="hlt">electronic</span> structures and magnetic properties of many rare-earth monopnictides are reviewed in this article. Possible candidate materials for spintronics devices from the rare-earth monopnictide family, i.e. high polarization (nominally half-metallic) ferromagnets and antiferromagnets, are identified. We attempt to provide a unified picture of the <span class="hlt">electronic</span> properties of these strongly correlated systems. The relative merits of several ab initio theoretical methods, useful in the study of the rare-earth monopnictides, are discussed. We present our current understanding of the possible half-metallicity, semiconductor-metal transitions, and magnetic orderings in the rare-earth monopnictides. Finally, we propose some potential strategies to improve the magnetic and <span class="hlt">electronic</span> properties of these candidate materials for spintronics devices. PMID:21694120</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030065832&hterms=Europium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DEuropium','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030065832&hterms=Europium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DEuropium"><span id="translatedtitle">Vertical <span class="hlt">Electron</span> <span class="hlt">Transport</span> through PbS-EuS Structures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wrotek, S.; Dybko, K.; Morawski, A.; Makosa, A.; Wosinski, T.; Figielski, T.; Tkaczyk, Z.; Lusakowska, E.; Story, T.; Sipatov, A. Yu</p> <p>2003-01-01</p> <p>Temperature dependence of current-voltage I-V characteristics and resistivity is studied in ferromagnetic PbS-EuS semiconductor tunnel structures grown on n-PbS (100) substrates. For the structures with a single (2-4 nm thick) ferromagnetic EuS <span class="hlt">electron</span> barrier we observe strongly non-linear I-V characteristics with an effective tunneling barrier height of 0.3-0.7 eV. The experimentally observed non-monotonic temperature dependence of the (normal to the plane of the structure) electrical resistance of these structures is discussed in terms of the <span class="hlt">electron</span> tunneling mechanism taking into account the temperature dependent shift of the band offsets at the EuS-PbS heterointerface as well as the exchange splitting of the <span class="hlt">electronic</span> states at the bottom of the conduction band of EuS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6984569','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6984569"><span id="translatedtitle">Adjoint <span class="hlt">transport</span> calculations for sensitivity analysis of the Hiroshima air-over-ground <span class="hlt">environment</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Broadhead, B.L.; Cacuci, D.G.; Pace, J.V. III</p> <p>1984-01-01</p> <p>A major effort within the US Dose Reassessment Program is aimed at recalculating the <span class="hlt">transport</span> of initial nuclear radiation in an air-over-ground <span class="hlt">environment</span>. This paper is the first report of results from adjoint calculations in the Hiroshima air-over-ground <span class="hlt">environment</span>. The calculations use a Hiroshima/Nagasaki multi-element ground, ENDF/B-V nuclear data, one-dimensional ANISN flux weighting for neutron and gamma cross sections, a source obtained by two-dimensional hydrodynamic and three-dimensional <span class="hlt">transport</span> calculations, and best-estimate atmospheric conditions from Japanese sources. 7 references, 2 figures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26206542','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26206542"><span id="translatedtitle">Critical Care <span class="hlt">Transport</span> Training: New Strides in Simulating the Austere <span class="hlt">Environment</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alfes, Celeste M; Steiner, Stephanie L; Manacci, Christopher F</p> <p>2015-01-01</p> <p>The air medical <span class="hlt">transport</span> arena requires the practitioner to develop clinical and diagnostic reasoning abilities to manage the dynamic needs of the patient in unstructured, uncertain, and often unforgiving <span class="hlt">environments</span>. High-fidelity simulation can be instrumental in training interprofessional flight teams to improve competency through quality and safe patient care during medical <span class="hlt">transport</span> that may otherwise take years to learn because of the inconsistency in real-world experiences. Because of the suboptimal circumstantial conditions inherent to critical care <span class="hlt">transport</span>, a helicopter simulator designed to discretely replicate the phases of flight and train teams in air medical <span class="hlt">transport</span> scenarios has been developed at the Dorothy Ebersbach Academic Center for Flight Nursing at the Frances Payne Bolton School of Nursing in Cleveland, OH. The goal is to prepare interdisciplinary critical care <span class="hlt">transport</span> flight teams in collaborative practice, research, and leadership through measurable and highly structured learning activities. PMID:26206542</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009APS..MARY33006B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009APS..MARY33006B"><span id="translatedtitle">On time-dependent counting statistics of mesoscopic <span class="hlt">electron</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belzig, Wolfgang</p> <p>2009-03-01</p> <p>Full counting statistics (FCS) has emerged as a key concept to understand quantum <span class="hlt">transport</span> in mesoscopic systems like heterostructures, quantum wires, and quantum dots. The knowlegde of the FCS not only enables to predict all measurable zero-frequency quantities accessible via charge detection, but also allows to identify the elementary <span class="hlt">transport</span> events and the correlations between them. We demonstrate this concept for a standard quantum point contact between normal and/or superconducting leads under dc- and ac-bias. [M. Vanevic, Yu. V. Nazarov, W. Belzig, Phys. Rev. Lett. 99, 076601 (2007)] Finally we address the question, how these concepts can be applied to time-resolved current measurements. [A. Bednorz and W. Belzig, Phys. Rev. Lett. 101, 206803 (2008)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/992528','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/992528"><span id="translatedtitle">Surface Charge- and Space-Dependent <span class="hlt">Transport</span> of Proteins in Crowded <span class="hlt">Environments</span> of Nanotailored Posts</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Choi, Chang Kyoung; Fowlkes, Jason Davidson; Retterer, Scott T; Siuti, Piro; Iyer, Sukanya; Doktycz, Mitchel John</p> <p>2010-01-01</p> <p>The reaction and diffusion of molecules across barriers and through crowded <span class="hlt">environments</span> is integral to biological system function and to separation technologies. Ordered, microfabricated post arrays are a promising route to creating synthetic barriers with controlled chemical and physical characteristics. They can be used to create crowded <span class="hlt">environments</span>, to mimic aspects of cellular membranes, and to serve as engineered replacements of polymer-based separation media. Here, the translational diffusion of fluorescein isothiocyante and various forms of green fluorescent protein (GFP), including 'supercharged' variants, are examined in a silicon-based post array <span class="hlt">environment</span>. The technique of fluorescence recovery after photobleaching (FRAP) is combined with analytical approximations and numerical simulations to assess the relative effects of reaction and diffusion on molecular <span class="hlt">transport</span>, respectively. FRAP experiments were conducted for 64 different cases where the molecular species, the density of the posts, and the chemical surface charge of the posts were varied. In all cases, the dense packing of the posts hindered the diffusive <span class="hlt">transport</span> of the fluorescent species. The supercharged GFPs strongly interacted with oppositely charged surfaces. With similar molecular and surface charges, <span class="hlt">transport</span> is primarily limited by hindered diffusion. For conventional, enhanced GFP in a positively charged surface <span class="hlt">environment</span>, <span class="hlt">transport</span> was limited by the coupled action of hindered diffusion and surface interaction with the posts. Quantification of the size-, space-, time-, and charge-dependent translational diffusion in the post array <span class="hlt">environments</span> can provide insight into natural processes and guide the design and development of selective membrane systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26958447','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26958447"><span id="translatedtitle">Smart <span class="hlt">Electronic</span> Laboratory Notebooks for the NIST Research <span class="hlt">Environment</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gates, Richard S; McLean, Mark J; Osborn, William A</p> <p>2015-01-01</p> <p>Laboratory notebooks have been a staple of scientific research for centuries for organizing and documenting ideas and experiments. Modern laboratories are increasingly reliant on <span class="hlt">electronic</span> data collection and analysis, so it seems inevitable that the digital revolution should come to the ordinary laboratory notebook. The most important aspect of this transition is to make the shift as comfortable and intuitive as possible, so that the creative process that is the hallmark of scientific investigation and engineering achievement is maintained, and ideally enhanced. The smart <span class="hlt">electronic</span> laboratory notebooks described in this paper represent a paradigm shift from the old pen and paper style notebooks and provide a host of powerful operational and documentation capabilities in an intuitive format that is available anywhere at any time. PMID:26958447</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4730679','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4730679"><span id="translatedtitle">Smart <span class="hlt">Electronic</span> Laboratory Notebooks for the NIST Research <span class="hlt">Environment</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gates, Richard S.; McLean, Mark J.; Osborn, William A.</p> <p>2015-01-01</p> <p>Laboratory notebooks have been a staple of scientific research for centuries for organizing and documenting ideas and experiments. Modern laboratories are increasingly reliant on <span class="hlt">electronic</span> data collection and analysis, so it seems inevitable that the digital revolution should come to the ordinary laboratory notebook. The most important aspect of this transition is to make the shift as comfortable and intuitive as possible, so that the creative process that is the hallmark of scientific investigation and engineering achievement is maintained, and ideally enhanced. The smart <span class="hlt">electronic</span> laboratory notebooks described in this paper represent a paradigm shift from the old pen and paper style notebooks and provide a host of powerful operational and documentation capabilities in an intuitive format that is available anywhere at any time. PMID:26958447</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PhRvB..93t5404L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PhRvB..93t5404L&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Electron</span> and phonon drag in thermoelectric <span class="hlt">transport</span> through coherent molecular conductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lü, Jing-Tao; Wang, Jian-Sheng; Hedegârd, Per; Brandbyge, Mads</p> <p>2016-05-01</p> <p>We study thermoelectric <span class="hlt">transport</span> through a coherent molecular conductor connected to two <span class="hlt">electron</span> and two phonon baths using the nonequilibrium Green's function method. We focus on the mutual drag between <span class="hlt">electron</span> and phonon <span class="hlt">transport</span> as a result of `momentum' transfer, which happens only when there are at least two phonon degrees of freedom. After deriving expressions for the linear drag coefficients, obeying the Onsager relation, we further investigate their effect on nonequilibrium <span class="hlt">transport</span>. We show that the drag effect is closely related to two other phenomena: (1) adiabatic charge pumping through a coherent conductor; (2) the current-induced nonconservative and effective magnetic forces on phonons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850014199','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850014199"><span id="translatedtitle">Discharge characteristics of dielectric materials examined in mono-, dual-, and spectral energy <span class="hlt">electron</span> charging <span class="hlt">environments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coakley, P.; Treadway, M.; Wild, N.; Kitterer, B.</p> <p>1985-01-01</p> <p>The effects of midenergy <span class="hlt">electrons</span> on the charge and discharge characteristics of spacecraft dielectric materials and the data base from which basic discharge models can be formulated is expanded. Thin dielectric materials were exposed to low, mid combined low and mid, and spectral energy <span class="hlt">electron</span> <span class="hlt">environments</span>. Three important results are presented: (1) it determined <span class="hlt">electron</span> <span class="hlt">environments</span> that lead to dielectric discharges at potentials less negative than -5 kV; (2) two types of discharges were identified that dominate the kinds of discharges seen; and (3) it is shown that, for the thin dielectric materials tested, the worst-case discharges observed in the various <span class="hlt">environments</span> are similar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18487807','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18487807"><span id="translatedtitle">Secure dissemination of <span class="hlt">electronic</span> healthcare records in distributed wireless <span class="hlt">environments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Belsis, Petros; Vassis, Dimitris; Skourlas, Christos; Pantziou, Grammati</p> <p>2008-01-01</p> <p>A new networking paradigm has emerged with the appearance of wireless computing. Among else ad-hoc networks, mobile and ubiquitous <span class="hlt">environments</span> can boost the performance of systems in which they get applied. Among else, medical <span class="hlt">environments</span> are a convenient example of their applicability. With the utilisation of wireless infrastructures, medical data may be accessible to healthcare practitioners, enabling continuous access to medical data. Due to the critical nature of medical information, the design and implementation of these infrastructures demands special treatment in order to meet specific requirements; among else, special care should be taken in order to manage interoperability, security, and in order to deal with bandwidth and hardware resource constraints that characterize the wireless topology. In this paper we present an architecture that attempts to deal with these issues; moreover, in order to prove the validity of our approach we have also evaluated the performance of our platform through simulation in different operating scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950023032','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950023032"><span id="translatedtitle">A hybrid <span class="hlt">electronically</span> scanned pressure module for cryogenic <span class="hlt">environments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chapman, J. J.; Hopson, P., Jr.; Kruse, N.</p> <p>1995-01-01</p> <p>Pressure is one of the most important parameters measured when testing models in wind tunnels. For models tested in the cryogenic <span class="hlt">environment</span> of the National Transonic Facility at NASA Langley Research Center, the technique of utilizing commercially available multichannel pressure modules inside the models is difficult due to the small internal volume of the models and the requirement of keeping the pressure transducer modules within an acceptable temperature range well above the -173 degrees C tunnel temperature. A prototype multichannel pressure transducer module has been designed and fabricated with stable, repeatable sensors and materials optimized for reliable performance in the cryogenic <span class="hlt">environment</span>. The module has 16 single crystal silicon piezoresistive pressure sensors electrostatically bonded to a metalized Pyrex substrate for sensing the wind tunnel model pressures. An integral temperature sensor mounted on each silicon micromachined pressure sensor senses real-time temperature fluctuations to within 0.1 degrees C to correct for thermally induced non-random sensor drift. The data presented here are from a prototype sensor module tested in the 0.3 M cryogenic tunnel and thermal equilibrium conditions in an environmental chamber which approximates the thermal <span class="hlt">environment</span> (-173 degrees C to +60 degrees C) of the National Transonic Facility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22413317','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22413317"><span id="translatedtitle"><span class="hlt">Electron</span> transfer activation of a second water channel for proton <span class="hlt">transport</span> in [FeFe]-hydrogenase</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sode, Olaseni; Voth, Gregory A.</p> <p>2014-12-14</p> <p>Hydrogenase enzymes are important because they can reversibly catalyze the production of molecular hydrogen. Proton <span class="hlt">transport</span> mechanisms have been previously studied in residue pathways that lead to the active site of the enzyme via residues Cys299 and Ser319. The importance of this pathway and these residues has been previously exhibited through site-specific mutations, which were shown to interrupt the enzyme activity. It has been shown recently that a separate water channel (WC2) is coupled with <span class="hlt">electron</span> <span class="hlt">transport</span> to the active site of the [FeFe]-hydrogenase. The water-mediated proton <span class="hlt">transport</span> mechanisms of the enzyme in different <span class="hlt">electronic</span> states have been studied using the multistate empirical valence bond reactive molecular dynamics method, in order to understand any role WC2 may have in facilitating the residue pathway in bringing an additional proton to the enzyme active site. In a single <span class="hlt">electronic</span> state A{sup 2−}, a water wire was formed through which protons can be <span class="hlt">transported</span> with a low free energy barrier. The remaining <span class="hlt">electronic</span> states were shown, however, to be highly unfavorable to proton <span class="hlt">transport</span> in WC2. A double amino acid substitution is predicted to obstruct proton <span class="hlt">transport</span> in <span class="hlt">electronic</span> state A{sup 2-} by closing a cavity that could otherwise fill with water near the proximal Fe of the active site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26648018','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26648018"><span id="translatedtitle"><span class="hlt">Electronic</span> and <span class="hlt">transport</span> properties of PSi@MoS2 nanocables.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sun, Cuicui; Zhang, Guiling; Shang, Yan; Yang, Zhao-Di; Sun, Xiaojun</p> <p>2016-02-14</p> <p><span class="hlt">Electronic</span> structures and <span class="hlt">transport</span> properties of prototype MoS2 nanotube (15, 0) nanocables, including undoped PSi@MoS2 and B- and P-doped PSi@MoS2 (where PSi refers to polysilane), are investigated using the density functional theory (DFT) and the non-equilibrium Green's function (NEGF) methods. It is found that <span class="hlt">transport</span> properties of two-probe systems by sandwiching finite long nanocables between two Au electrodes are basically in agreement with the <span class="hlt">electronic</span> structures of their corresponding infinitely long systems. Encapsulating undoped and doped PSi nanowires inside the MoS2 nanotubes could not significantly affect the <span class="hlt">electronic</span> and <span class="hlt">transport</span> properties. B-doping and P-doping upon PSi play different roles in the <span class="hlt">electronic</span> and <span class="hlt">transport</span> properties. B-doping may exert constructive and destructive effects on <span class="hlt">electron</span> <span class="hlt">transport</span> depending on its position and applied bias direction, while P-doping displays a negligible effect. In addition, we found that bi-doping by two adjacent B atoms could slightly enhance the conductivity. These results could offer some clues for conducting experiments to achieve nanoelectronic devices with intrinsic <span class="hlt">transport</span> properties of MoS2 nanotubes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006NucFu..46..133I&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006NucFu..46..133I&link_type=ABSTRACT"><span id="translatedtitle">Comparison of transient <span class="hlt">electron</span> heat <span class="hlt">transport</span> in LHD helical and JT-60U tokamak plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Inagaki, S.; Takenaga, H.; Ida, K.; Isayama, A.; Tamura, N.; Takizuka, T.; Shimozuma, T.; Kamada, Y.; Kubo, S.; Miura, Y.; Nagayama, Y.; Kawahata, K.; Sudo, S.; Ohkubo, K.; LHD Experimental Group; JT-60 Team</p> <p>2006-01-01</p> <p>Transient <span class="hlt">transport</span> experiments are performed in plasmas with and without internal <span class="hlt">transport</span> barriers (ITB) on LHD and JT-60U. The dependence of χe on the <span class="hlt">electron</span> temperature, Te, and on the <span class="hlt">electron</span> temperature gradient, ∇Te, is analysed with an empirical non-linear heat <span class="hlt">transport</span> model. In plasmas without an ITB, two different types of non-linearity of the <span class="hlt">electron</span> heat <span class="hlt">transport</span> are observed from cold/heat pulse propagation: the χe depends on Te and ∇Te in JT-60U, while the ∇Te dependence is weak in LHD. Inside the ITB region, there is none or weak ∇Te dependence both in LHD and JT-60U. Growth of the cold pulse driven by the negative Te dependence of χe is observed inside the ITB region (LHD) and near the boundary of the ITB region (JT-60U).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22492756','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22492756"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> characterization of silicon wafers by spatially resolved steady-state photocarrier radiometric imaging</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Qian; Li, Bincheng</p> <p>2015-09-28</p> <p>Spatially resolved steady-state photocarrier radiometric (PCR) imaging technique is developed to characterize the <span class="hlt">electronic</span> <span class="hlt">transport</span> properties of silicon wafers. Based on a nonlinear PCR theory, simulations are performed to investigate the effects of <span class="hlt">electronic</span> <span class="hlt">transport</span> parameters (the carrier lifetime, the carrier diffusion coefficient, and the front surface recombination velocity) on the steady-state PCR intensity profiles. The <span class="hlt">electronic</span> <span class="hlt">transport</span> parameters of an n-type silicon wafer are simultaneously determined by fitting the measured steady-state PCR intensity profiles to the three-dimensional nonlinear PCR model. The determined <span class="hlt">transport</span> parameters are in good agreement with the results obtained by the conventional modulated PCR technique with multiple pump beam radii.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1065345','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1065345"><span id="translatedtitle">Local Pathways in Coherent <span class="hlt">Electron</span> <span class="hlt">Transport</span> through Iron Porphyrin Complexes: A Challenge for First-Principles <span class="hlt">Transport</span> Calculations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Herrmann, C.; Solomon, G.C.; Ratner, Mark A.</p> <p>2010-12-09</p> <p>We investigate the coherent <span class="hlt">electron</span> <span class="hlt">transport</span> properties of a selection of iron porphyrin complexes in their low-spin and high-spin states, binding the system to metallic electrodes with three different substitution patterns. We use a study of the local transmission through the complexes and their molecular orbitals to show the role of the various components of the molecular structure in mediating <span class="hlt">electron</span> <span class="hlt">transport</span>. While there are energies where the metal center and the axial ligands participate in <span class="hlt">transport</span>, in the off-resonant energy range, these components simply form a scaffold, and the <span class="hlt">transport</span> is dominated by transmission through the porphyrin macrocyle alone. This is still true when going from the low-spin to the high-spin state, except that now, an additional iron-centered MO contributes to <span class="hlt">transport</span> in the formerly off-resonant region. It is found that while the choice of the exchange-correlation functional can strongly influence the quantitative results, our qualitative conclusions hold irrespective of the functional employed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.109e2901I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.109e2901I"><span id="translatedtitle">The charge <span class="hlt">transport</span> mechanism and <span class="hlt">electron</span> trap nature in thermal oxide on silicon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Islamov, Damir R.; Gritsenko, Vladimir A.; Perevalov, Timofey V.; Orlov, Oleg M.; Krasnikov, Gennady Ya.</p> <p>2016-08-01</p> <p>The charge <span class="hlt">transport</span> mechanism of <span class="hlt">electron</span> via traps in amorphous SiO2 has been studied. <span class="hlt">Electron</span> <span class="hlt">transport</span> is limited by phonon-assisted tunneling between traps. Thermal and optical trap energies Wt=1.6 eV, Wopt=3.2 eV, respectively, were determined. Charge flowing leads to oxygen vacancies generation, and the leakage current increases due to the increase of charge trap density. Long-time annealing at high temperatures decreased the leakage current to initial values due to oxygen vacancies recombination with interstitial oxygen. It is found that the oxygen vacancies act as <span class="hlt">electron</span> traps in SiO2.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22472123','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22472123"><span id="translatedtitle">Kinetics of vertical <span class="hlt">transport</span> and localization of <span class="hlt">electrons</span> in strained semiconductor supperlattices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gerchikov, L. G. Mamaev, Yu. A.; Yashin, Yu. P.</p> <p>2015-08-15</p> <p>The kinetics of vertical <span class="hlt">electron</span> <span class="hlt">transport</span> in a semiconductor superlattice is considered taking into account partial localization of <span class="hlt">electrons</span>. The time dependences of photoemission currents from samples based on a strained semiconductor superlattice calculated by numerically solving the kinetic equation are in good agreement with experimental data. Comparison of the theory with experiment makes it possible to determine the characteristic <span class="hlt">electron</span> localization and thermoactivation times, the diffusion length, and losses of photoelectrons in the superlattice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20719414','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20719414"><span id="translatedtitle">Novel freestanding nanotube devices for combining TEM and <span class="hlt">electron</span> diffraction with Raman and <span class="hlt">Transport</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Meyer, Jannik C.; Obergfell, Dirk; Roth, Siegmar; Paillet, Matthieu; Sauvajol, Jean-Louis; Neumann, Anita; Duesberg, Georg</p> <p>2005-09-27</p> <p>A versatile procedure for combining high-resolution transmission <span class="hlt">electron</span> microscopy (TEM) and <span class="hlt">electron</span> diffraction with Raman spectroscopy and <span class="hlt">transport</span> measurements on the very same nanotube is presented. For this we prepare free-standing structures on the corner of a substrate by <span class="hlt">electron</span> beam lithography and an etching process. Further, this procedure makes possible a TEM quality control of nanotubes grown directly on the substrate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19810028028&hterms=earth+environment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dearth%2Benvironment','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19810028028&hterms=earth+environment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dearth%2Benvironment"><span id="translatedtitle">Ion and <span class="hlt">electron</span> pulses observed in the earth's magnetospheric <span class="hlt">environment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lin, Y. C.; Fan, C. Y.; Gloeckler, G.; Hovestadt, D.</p> <p>1980-01-01</p> <p>Pulses of about 100 keV ions and <span class="hlt">electrons</span> of time duration of several minutes are frequently detected in the earth's magnetotail and in the upstream region from the earth's bow shock. The distribution of the locations of the IMP 7 satellite where the particles were observed over the period from Sept. 29, 1972 to Oct. 6, 1973 is presented. The physical implications of these findings as related to (1) the source locations and (2) the dynamic nature of the acceleration and propagation of these particles are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004MPLB...18..847R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004MPLB...18..847R"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">Transport</span> and Thermopower in Aperiodic DNA Sequences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roche, Stephan; Maciá, Enrique</p> <p></p> <p>A detailed study of charge <span class="hlt">transport</span> properties of synthetic and genomic DNA sequences is reported. Genomic sequences of the Chromosome 22, λ-bacteriophage, and D1s80 genes of Human and Pygmy chimpanzee are considered in this work, and compared with both periodic and quasiperiodic (Fibonacci) sequences of nucleotides. Charge transfer efficiency is compared for all these different sequences, and large variations in charge transfer efficiency, stemming from sequence-dependent effects, are reported. In addition, basic characteristics of tunneling currents, including contact effects, are described. Finally, the thermoelectric power of nucleobases connected in between metallic contacts at different temperatures is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93t5408R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93t5408R"><span id="translatedtitle">Fluctuating-bias controlled <span class="hlt">electron</span> <span class="hlt">transport</span> in molecular junctions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ridley, Michael; MacKinnon, Angus; Kantorovich, Lev</p> <p>2016-05-01</p> <p>We consider the problem of <span class="hlt">transport</span> through a multiterminal molecular junction in the presence of a stochastic bias, which can also be used to describe <span class="hlt">transport</span> through fluctuating molecular energy levels. To describe these effects, we first make a simple extension of our previous work [Phys. Rev. B 91, 125433 (2015), 10.1103/PhysRevB.91.125433] to show that the problem of tunneling through noisy energy levels can be mapped onto the problem of a noisy driving bias, which appears in the Kadanoff-Baym equations for this system in an analogous manner to the driving term in the Langevin equation for a classical circuit. This formalism uses the nonequilibrium Green's function method to obtain analytically closed formulas for <span class="hlt">transport</span> quantities within the wide-band limit approximation for an arbitrary time-dependent bias and it is automatically partition free. We obtain exact closed formulas for both the colored and white noise-averaged current at all times. In the long-time limit, these formulas possess a Landauer-Büttiker-type structure which enables the extraction of an effective transmission coefficient for the <span class="hlt">transport</span>. Expanding the Fermi function into a series of simple poles, we find an exact formal relation between the parameters which characterize the bias fluctuations and the poles of the Fermi function. This enables us to describe the effect of the temperature and the strength of the fluctuations on the averaged current which we interpret as a quantum analog to the classical fluctuation-dissipation theorem. We use these results to convincingly refute some recent results on the multistability of the current through a fluctuating level, simultaneously verifying that our formalism satisfies some well-known theorems on the asymptotic current. Finally, we present numerical results for the current through a molecular chain which demonstrate a transition from nonlinear to linear I -V characteristics as the strength of fluctuations is increased, as well as a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93x5415G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93x5415G"><span id="translatedtitle">Inelastic vibrational signals in <span class="hlt">electron</span> <span class="hlt">transport</span> across graphene nanoconstrictions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gunst, Tue; Markussen, Troels; Stokbro, Kurt; Brandbyge, Mads</p> <p>2016-06-01</p> <p>We present calculations of the inelastic vibrational signals in the electrical current through a graphene nanoconstriction. We find that the inelastic signals are only present when the Fermi-level position is tuned to <span class="hlt">electron</span> transmission resonances, thus, providing a fingerprint which can link an <span class="hlt">electron</span> transmission resonance to originate from the nanoconstriction. The calculations are based on a novel first-principles method which includes the phonon broadening due to coupling with phonons in the electrodes. We find that the signals are modified due to the strong coupling to the electrodes, however, still remain as robust fingerprints of the vibrations in the nanoconstriction. We investigate the effect of including the full self-consistent potential drop due to finite bias and gate doping on the calculations and find this to be of minor importance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4756276','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4756276"><span id="translatedtitle">Distribution and dynamics of <span class="hlt">electron</span> <span class="hlt">transport</span> complexes in cyanobacterial thylakoid membranes☆</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Lu-Ning</p> <p>2016-01-01</p> <p>The cyanobacterial thylakoid membrane represents a system that can carry out both oxygenic photosynthesis and respiration simultaneously. The organization, interactions and mobility of components of these two <span class="hlt">electron</span> <span class="hlt">transport</span> pathways are indispensable to the biosynthesis of thylakoid membrane modules and the optimization of bioenergetic <span class="hlt">electron</span> flow in response to environmental changes. These are of fundamental importance to the metabolic robustness and plasticity of cyanobacteria. This review summarizes our current knowledge about the distribution and dynamics of <span class="hlt">electron</span> <span class="hlt">transport</span> components in cyanobacterial thylakoid membranes. Global understanding of the principles that govern the dynamic regulation of <span class="hlt">electron</span> <span class="hlt">transport</span> pathways in nature will provide a framework for the design and synthetic engineering of new bioenergetic machinery to improve photosynthesis and biofuel production. This article is part of a Special Issue entitled: Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux. PMID:26619924</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26619924','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26619924"><span id="translatedtitle">Distribution and dynamics of <span class="hlt">electron</span> <span class="hlt">transport</span> complexes in cyanobacterial thylakoid membranes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Lu-Ning</p> <p>2016-03-01</p> <p>The cyanobacterial thylakoid membrane represents a system that can carry out both oxygenic photosynthesis and respiration simultaneously. The organization, interactions and mobility of components of these two <span class="hlt">electron</span> <span class="hlt">transport</span> pathways are indispensable to the biosynthesis of thylakoid membrane modules and the optimization of bioenergetic <span class="hlt">electron</span> flow in response to environmental changes. These are of fundamental importance to the metabolic robustness and plasticity of cyanobacteria. This review summarizes our current knowledge about the distribution and dynamics of <span class="hlt">electron</span> <span class="hlt">transport</span> components in cyanobacterial thylakoid membranes. Global understanding of the principles that govern the dynamic regulation of <span class="hlt">electron</span> <span class="hlt">transport</span> pathways in nature will provide a framework for the design and synthetic engineering of new bioenergetic machinery to improve photosynthesis and biofuel production. This article is part of a Special Issue entitled: Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7091775','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7091775"><span id="translatedtitle">Nonlocal heat <span class="hlt">transport</span> by non-Maxwellian <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Swartz, K.; Short, R.W.</p> <p>1984-03-30</p> <p>The generalization of the Spitzer-Harm solution to steep density and temperature gradients requires the computation of the appropriate non-Maxwellian isotropic part of the <span class="hlt">electron</span> distribution. We develop analytic solutions for a steady state, high-Z plasma, employing the diffusion approximation. Applications of our solution include computation of the resulting heat flux, thermal smoothing of transverse temperature perturbations, and modification of linear heat flow instabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=227117','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=227117"><span id="translatedtitle">The knowledge workstation: an <span class="hlt">electronic</span> <span class="hlt">environment</span> for knowledge management.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lucier, R E; Matheson, N W; Butter, K A; Reynolds, R E</p> <p>1988-01-01</p> <p>This paper focuses on the creation of the IAIMS workstation in the context of the outcomes of a year-long IAIMS strategic planning process at the Johns Hopkins Medical Institutions (JHMI). These outcomes include a long-term institutional vision for a functional knowledge management <span class="hlt">environment</span>, a JHMI IAIMS model, a strategic plan, and two model prototypes. The functional requirements and specific implementation strategies for the IAIMS workstation, the prototype for managing the knowledge base of the published biomedical literature, are discussed in detail. PMID:3416102</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/3416102','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/3416102"><span id="translatedtitle">The knowledge workstation: an <span class="hlt">electronic</span> <span class="hlt">environment</span> for knowledge management.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lucier, R E; Matheson, N W; Butter, K A; Reynolds, R E</p> <p>1988-07-01</p> <p>This paper focuses on the creation of the IAIMS workstation in the context of the outcomes of a year-long IAIMS strategic planning process at the Johns Hopkins Medical Institutions (JHMI). These outcomes include a long-term institutional vision for a functional knowledge management <span class="hlt">environment</span>, a JHMI IAIMS model, a strategic plan, and two model prototypes. The functional requirements and specific implementation strategies for the IAIMS workstation, the prototype for managing the knowledge base of the published biomedical literature, are discussed in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23733643','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23733643"><span id="translatedtitle"><span class="hlt">Transport</span> of gases between the <span class="hlt">environment</span> and alveoli--theoretical foundations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Butler, James P; Tsuda, Akira</p> <p>2011-07-01</p> <p>The <span class="hlt">transport</span> of oxygen and carbon dioxide in the gas phase from the ambient <span class="hlt">environment</span> to and from the alveolar gas/blood interface is accomplished through the tracheobronchial tree, and involves mechanisms of bulk or convective <span class="hlt">transport</span> and diffusive net <span class="hlt">transport</span>. The geometry of the airway tree and the fluid dynamics of these two <span class="hlt">transport</span> processes combine in such a way that promotes a classical fractionation of ventilation into dead space and alveolar ventilation, respectively. This simple picture continues to capture much of the essence of gas phase <span class="hlt">transport</span>. On the other hand, a more detailed look at the interaction of convection and diffusion leads to significant new issues, many of which remain open questions. These are associated with parallel and serial inhomogeneities especially within the distal acinar units, velocity profiles in distal airways and terminal spaces subject to moving boundary conditions, and the serial <span class="hlt">transport</span> of respiratory gases within the complex acinar architecture. This article focuses specifically on the theoretical foundations of gas <span class="hlt">transport</span>, addressing two broad areas. The first deals with the reasons why the classical picture of alveolar and dead space ventilation is so successful; the second examines the underlying assumptions within current approximations to convective and diffusive <span class="hlt">transport</span>, and how they interact to effect net gas exchange.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22486492','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22486492"><span id="translatedtitle">Study of <span class="hlt">electron</span> <span class="hlt">transport</span> in a Hall thruster by axial–radial fully kinetic particle simulation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cho, Shinatora Kubota, Kenichi; Funaki, Ikkoh; Watanabe, Hiroki; Iihara, Shigeyasu; Fuchigami, Kenji; Uematsu, Kazuo</p> <p>2015-10-15</p> <p><span class="hlt">Electron</span> <span class="hlt">transport</span> across a magnetic field in a magnetic-layer-type Hall thruster was numerically investigated for the future predictive modeling of Hall thrusters. The discharge of a 1-kW-class magnetic-layer-type Hall thruster designed for high-specific-impulse operation was modeled using an r-z two-dimensional fully kinetic particle code with and without artificial <span class="hlt">electron</span>-diffusion models. The thruster performance results showed that both <span class="hlt">electron</span> <span class="hlt">transport</span> models captured the experimental result within discrepancies less than 20% in thrust and discharge current for all the simulated operation conditions. The <span class="hlt">electron</span> cross-field <span class="hlt">transport</span> mechanism of the so-called anomalous diffusion was self-consistently observed in the simulation without artificial diffusion models; the effective <span class="hlt">electron</span> mobility was two orders of magnitude higher than the value obtained using the classical diffusion theory. To account for the self-consistently observed anomalous <span class="hlt">transport</span>, the oscillation of plasma properties was speculated. It was suggested that the enhanced random-walk diffusion due to the velocity oscillation of low-frequency <span class="hlt">electron</span> flow could explain the observed anomalous diffusion within an order of magnitude. The dominant oscillation mode of the <span class="hlt">electron</span> flow velocity was found to be 20 kHz, which was coupled to electrostatic oscillation excited by global ionization instability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016AIPA....6f5303A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016AIPA....6f5303A&link_type=ABSTRACT"><span id="translatedtitle">Low resistivity ZnO-GO <span class="hlt">electron</span> <span class="hlt">transport</span> layer based CH3NH3PbI3 solar cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahmed, Muhammad Imran; Hussain, Zakir; Mujahid, Mohammad; Khan, Ahmed Nawaz; Javaid, Syed Saad; Habib, Amir</p> <p>2016-06-01</p> <p>Perovskite based solar cells have demonstrated impressive performances. Controlled <span class="hlt">environment</span> synthesis and expensive hole <span class="hlt">transport</span> material impede their potential commercialization. We report ambient air synthesis of hole <span class="hlt">transport</span> layer free devices using ZnO-GO as <span class="hlt">electron</span> selective contacts. Solar cells fabricated with hole <span class="hlt">transport</span> layer free architecture under ambient air conditions with ZnO as <span class="hlt">electron</span> selective contact achieved an efficiency of 3.02%. We have demonstrated that by incorporating GO in ZnO matrix, low resistivity <span class="hlt">electron</span> selective contacts, critical to improve the performance, can be achieved. We could achieve max efficiency of 4.52% with our completed devices for ZnO: GO composite. Impedance spectroscopy confirmed the decrease in series resistance and an increase in recombination resistance with inclusion of GO in ZnO matrix. Effect of temperature on completed devices was investigated by recording impedance spectra at 40 and 60 oC, providing indirect evidence of the performance of solar cells at elevated temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25143589','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25143589"><span id="translatedtitle">Shewanella oneidensis MR-1 nanowires are outer membrane and periplasmic extensions of the extracellular <span class="hlt">electron</span> <span class="hlt">transport</span> components.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pirbadian, Sahand; Barchinger, Sarah E; Leung, Kar Man; Byun, Hye Suk; Jangir, Yamini; Bouhenni, Rachida A; Reed, Samantha B; Romine, Margaret F; Saffarini, Daad A; Shi, Liang; Gorby, Yuri A; Golbeck, John H; El-Naggar, Mohamed Y</p> <p>2014-09-01</p> <p>Bacterial nanowires offer an extracellular <span class="hlt">electron</span> <span class="hlt">transport</span> (EET) pathway for linking the respiratory chain of bacteria to external surfaces, including oxidized metals in the <span class="hlt">environment</span> and engineered electrodes in renewable energy devices. Despite the global, environmental, and technological consequences of this biotic-abiotic interaction, the composition, physiological relevance, and <span class="hlt">electron</span> <span class="hlt">transport</span> mechanisms of bacterial nanowires remain unclear. We report, to our knowledge, the first in vivo observations of the formation and respiratory impact of nanowires in the model metal-reducing microbe Shewanella oneidensis MR-1. Live fluorescence measurements, immunolabeling, and quantitative gene expression analysis point to S. oneidensis MR-1 nanowires as extensions of the outer membrane and periplasm that include the multiheme cytochromes responsible for EET, rather than pilin-based structures as previously thought. These membrane extensions are associated with outer membrane vesicles, structures ubiquitous in Gram-negative bacteria, and are consistent with bacterial nanowires that mediate long-range EET by the previously proposed multistep redox hopping mechanism. Redox-functionalized membrane and vesicular extensions may represent a general microbial strategy for <span class="hlt">electron</span> <span class="hlt">transport</span> and energy distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1170479','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1170479"><span id="translatedtitle">Shewanella oneidensis MR-1 Nanowires are Outer Membrane and Periplasmic Extensions of the Extracellular <span class="hlt">Electron</span> <span class="hlt">Transport</span> Components</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pirbadian, S.; Barchinger, S. E.; Leung, K. M.; Byun, H. S.; Jangir, Y.; Bouhenni, Rachida; Reed, Samantha B.; Romine, Margaret F.; Saffarini, Daad; Shi, Liang; Gorby, Yuri A.; Golbeck, J. H.; El-Naggar, Mohamed Y.</p> <p>2014-08-20</p> <p>Bacterial nanowires offer an extracellular <span class="hlt">electron</span> <span class="hlt">transport</span> (EET) pathway for linking the respiratory chain of bacteria to external surfaces, including oxidized metals in the <span class="hlt">environment</span> and engineered electrodes in renewable energy devices. Despite the global, environmental, and technological consequences of this biotic-abiotic interaction, the composition, physiological relevance, and <span class="hlt">electron</span> <span class="hlt">transport</span> mechanisms of bacterial nanowires remain unclear. We report the first in vivo observations of the formation and respiratory impact of nanowires in the model metal-reducing microbe Shewanella neidensis MR-1. Using live fluorescence measurements, immunolabeling, and quantitative gene expression analysis, we report that S. oneidensis MR-1 nanowires are extensions of the outer membrane and periplasm that include the multiheme cytochromes responsible for EET, rather than pilin-based structures, as previously thought. These bacterial nanowires were also associated with outer membrane vesicles and vesicle chains, structures ubiquitous in gram-negative bacteria. Redoxfunctionalized membrane and vesicular extensions may represent a general microbial strategy for <span class="hlt">electron</span> <span class="hlt">transport</span> and energy distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4156777','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4156777"><span id="translatedtitle">Shewanella oneidensis MR-1 nanowires are outer membrane and periplasmic extensions of the extracellular <span class="hlt">electron</span> <span class="hlt">transport</span> components</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pirbadian, Sahand; Barchinger, Sarah E.; Leung, Kar Man; Byun, Hye Suk; Jangir, Yamini; Bouhenni, Rachida A.; Reed, Samantha B.; Romine, Margaret F.; Saffarini, Daad A.; Shi, Liang; Gorby, Yuri A.; Golbeck, John H.; El-Naggar, Mohamed Y.</p> <p>2014-01-01</p> <p>Bacterial nanowires offer an extracellular <span class="hlt">electron</span> <span class="hlt">transport</span> (EET) pathway for linking the respiratory chain of bacteria to external surfaces, including oxidized metals in the <span class="hlt">environment</span> and engineered electrodes in renewable energy devices. Despite the global, environmental, and technological consequences of this biotic–abiotic interaction, the composition, physiological relevance, and <span class="hlt">electron</span> <span class="hlt">transport</span> mechanisms of bacterial nanowires remain unclear. We report, to our knowledge, the first in vivo observations of the formation and respiratory impact of nanowires in the model metal-reducing microbe Shewanella oneidensis MR-1. Live fluorescence measurements, immunolabeling, and quantitative gene expression analysis point to S. oneidensis MR-1 nanowires as extensions of the outer membrane and periplasm that include the multiheme cytochromes responsible for EET, rather than pilin-based structures as previously thought. These membrane extensions are associated with outer membrane vesicles, structures ubiquitous in Gram-negative bacteria, and are consistent with bacterial nanowires that mediate long-range EET by the previously proposed multistep redox hopping mechanism. Redox-functionalized membrane and vesicular extensions may represent a general microbial strategy for <span class="hlt">electron</span> <span class="hlt">transport</span> and energy distribution. PMID:25143589</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880052987&hterms=Neutralization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DNeutralization','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880052987&hterms=Neutralization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DNeutralization"><span id="translatedtitle">Energy <span class="hlt">transport</span> by energetic <span class="hlt">electrons</span> released during solar flares. II - Current filamentation and plasma heating</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winglee, R. M.; Dulk, G. A.; Pritchett, P. L.</p> <p>1988-01-01</p> <p>Two-dimensional electrostatic particle simulations are performed in order to investigate energy <span class="hlt">transport</span> associated with the propagation of energetic <span class="hlt">electrons</span> through a flaring flux tube. Results indicate that as the energetic <span class="hlt">electrons</span> flow outward, a return current of ambient plasma <span class="hlt">electrons</span> is drawn inward (to maintain quasi-neutrality) which can be spatially separate from the primary current carried by the energetic <span class="hlt">electrons</span>. Return current <span class="hlt">electrons</span> are shown to accumulate on either side of the acceleration region of the energetic <span class="hlt">electrons</span>, and depletions of ambient plasma <span class="hlt">electrons</span> develop in the return current regions. Plasma ions accelerate across the field lines to produce current closure or charge neutralization, achieving energies comparable to those of the energetic <span class="hlt">electrons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Transportation+AND+affects+AND+air+AND+pollution&id=ED439909','ERIC'); return false;" href="http://eric.ed.gov/?q=Transportation+AND+affects+AND+air+AND+pollution&id=ED439909"><span id="translatedtitle">Going Places, Making Choices: <span class="hlt">Transportation</span> and the <span class="hlt">Environment</span>. Curriculum Designed for Grades 9-12.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>National 4-H Council, Chevy Chase, MD.</p> <p></p> <p>This curriculum packet includes a teacher's introduction and five curriculum units that explore how <span class="hlt">transportation</span> needs affect the <span class="hlt">environment</span>, including the quality of air and water, habitat, and global climate. These materials encourage teens to apply wisdom, ingenuity, and sound science to the choices they make. Units are: (1)…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5623964','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5623964"><span id="translatedtitle">Factors influencing the <span class="hlt">transport</span> of actinides in the groundwater <span class="hlt">environment</span>. Final report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sheppard, J.C.; Kittrick, J.A.</p> <p>1983-07-31</p> <p>This report summarizes investigations of factors that significantly influence the <span class="hlt">transport</span> of actinide cations in the groundwater <span class="hlt">environment</span>. Briefly, measurements of diffusion coefficients for Am(III), Cm(III), and Np(V) in moist US soils indicated that diffusion is negligible compared to mass <span class="hlt">transport</span> in flowing groundwater. Diffusion coefficients do, however, indicate that, in the absence of flowing water, actinide elements will migrate only a few centimeters in a thousand years. The remaining investigations were devoted to the determination of distribution ratios (K/sub d/s) for representative US soils, factors influencing them, and chemical and physical processes related to <span class="hlt">transport</span> of actinides in groundwaters. The computer code GARD was modified to include complex formation to test the importance of humic acid complexing on the rate of <span class="hlt">transport</span> of actinides in groundwaters. Use of the formation constant and a range of humic acid, even at rather low concentrations of 10/sup -5/ to 10/sup -6/ molar, significantly increases the actinide <span class="hlt">transport</span> rate in a flowing aquifer. These computer calculations show that any strong complexing agent will have a similar effect on actinide <span class="hlt">transport</span> in the groundwater <span class="hlt">environment</span>. 32 references, 9 figures.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25105780','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25105780"><span id="translatedtitle"><span class="hlt">Electronic</span> conduction properties of indium tin oxide: single-particle and many-body <span class="hlt">transport</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Juhn-Jong; Li, Zhi-Qing</p> <p>2014-08-27</p> <p>Indium tin oxide (Sn-doped In2O3-δ or ITO) is a very interesting and technologically important transparent conducting oxide. This class of material has been extensively investigated for decades, with research efforts mostly focusing on the application aspects. The fundamental issues of the <span class="hlt">electronic</span> conduction properties of ITO from room temperature down to liquid-helium temperatures have rarely been addressed thus far. Studies of the electrical-<span class="hlt">transport</span> properties over a wide range of temperature are essential to unravelling the underlying <span class="hlt">electronic</span> dynamics and microscopic <span class="hlt">electronic</span> parameters. In this topical review, we show that one can learn rich physics in ITO material, including the semi-classical Boltzmann <span class="hlt">transport</span>, the quantum-interference <span class="hlt">electron</span> <span class="hlt">transport</span>, as well as the many-body Coulomb <span class="hlt">electron-electron</span> interaction effects in the presence of disorder and inhomogeneity (granularity). To fully reveal the numerous avenues and unique opportunities that the ITO material has provided for fundamental condensed matter physics research, we demonstrate a variety of charge <span class="hlt">transport</span> properties in different forms of ITO structures, including homogeneous polycrystalline thin and thick films, homogeneous single-crystalline nanowires and inhomogeneous ultrathin films. In this manner, we not only address new physics phenomena that can arise in ITO but also illustrate the versatility of the stable ITO material forms for potential technological applications. We emphasize that, microscopically, the novel and rich <span class="hlt">electronic</span> conduction properties of ITO originate from the inherited robust free-<span class="hlt">electron</span>-like energy bandstructure and low-carrier concentration (as compared with that in typical metals) characteristics of this class of material. Furthermore, a low carrier concentration leads to slow <span class="hlt">electron</span>-phonon relaxation, which in turn causes the experimentally observed (i) a small residual resistance ratio, (ii) a linear <span class="hlt">electron</span> diffusion thermoelectric power in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3396541','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3396541"><span id="translatedtitle">Control of <span class="hlt">electron</span> <span class="hlt">transport</span> routes through redox-regulated redistribution of respiratory complexes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Lu-Ning; Bryan, Samantha J.; Huang, Fang; Yu, Jianfeng; Nixon, Peter J.; Rich, Peter R.; Mullineaux, Conrad W.</p> <p>2012-01-01</p> <p>In cyanobacteria, respiratory <span class="hlt">electron</span> <span class="hlt">transport</span> takes place in close proximity to photosynthetic <span class="hlt">electron</span> <span class="hlt">transport</span>, because the complexes required for both processes are located within the thylakoid membranes. The balance of <span class="hlt">electron</span> <span class="hlt">transport</span> routes is crucial for cell physiology, yet the factors that control the predominance of particular pathways are poorly understood. Here we use a combination of tagging with green fluorescent protein and confocal fluorescence microscopy in live cells of the cyanobacterium Synechococcus elongatus PCC 7942 to investigate the distribution on submicron scales of two key respiratory <span class="hlt">electron</span> donors, type-I NAD(P)H dehydrogenase (NDH-1) and succinate dehydrogenase (SDH). When cells are grown under low light, both complexes are concentrated in discrete patches in the thylakoid membranes, about 100–300 nm in diameter and containing tens to hundreds of complexes. Exposure to moderate light leads to redistribution of both NDH-1 and SDH such that they become evenly distributed within the thylakoid membranes. The effects of <span class="hlt">electron</span> <span class="hlt">transport</span> inhibitors indicate that redistribution of respiratory complexes is triggered by changes in the redox state of an <span class="hlt">electron</span> carrier close to plastoquinone. Redistribution does not depend on de novo protein synthesis, and it is accompanied by a major increase in the probability that respiratory <span class="hlt">electrons</span> are transferred to photosystem I rather than to a terminal oxidase. These results indicate that the distribution of complexes on the scale of 100–300 nm controls the partitioning of reducing power and that redistribution of <span class="hlt">electron</span> <span class="hlt">transport</span> complexes on these scales is a physiological mechanism to regulate the pathways of <span class="hlt">electron</span> flow. PMID:22733774</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1327459','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1327459"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">transport</span> across glycerol monooleate bilayer lipid membranes facilitated by magnesium etiochlorin.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Feldberg, S W; Armen, G H; Bell, J A; Chang, C K; Wang, C B</p> <p>1981-01-01</p> <p>The <span class="hlt">transport</span> of <span class="hlt">electrons</span> across biological membranes is believed to play an important role in many biophenomena. Although there have been many examples of systems which may be <span class="hlt">transporting</span> <span class="hlt">electrons</span> across Mueller-Rudin bilayer lipid membranes (blm), none has been well characterized. The system we describe here comprises a glycerol monooleate blm containing a magnesium etiochlorin (Mg-C) separating two aqueous phases each containing ferricyanide, ferrocyanide, KCl, and a platinum electrode. The E0s for the Mg-C+/Mg-C and ferri-/ferrocyanide couples are 0.22 and 0.24 V vs. SCE. Thus the MG-C+/Mb-C system is easily poised by the ferri-/ferrocyanide system. When the potentials of the ferri-/ferrocyanide couples are different on each side of the blm we show that the open-circuit membrane potential nearly equals the difference between the redox potentials. This is unequivocal evidence that <span class="hlt">electrons</span> are being transferred across the blm from one aqueous phase to the other. On the basis of these experiments we deduce that <span class="hlt">electron</span> <span class="hlt">transport</span> is the major charge <span class="hlt">transport</span> mechanism. When redox potentials are the same on each side of the blm, the conductance of the membrane can be greater than 10(-3) S/cm2. The conductance is proportional to the second power of the concentration of Mg-C in the membrane-forming mixture. A number of additional experiments are described which attempt to elucidate the mechanism of <span class="hlt">electron</span> transfer. We believe that our data are consistent with the idea of an <span class="hlt">electron</span>-hopping mechanism in which the transmembrane <span class="hlt">electron</span> <span class="hlt">transport</span> occurs by a series of second-order <span class="hlt">electron</span> transfers between membrane-bound <span class="hlt">electron</span> donors (Mg-C) and acceptors (Mg-C+). Alternative explanations are presented. PMID:7213929</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4885465','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4885465"><span id="translatedtitle">Built <span class="hlt">Environment</span> and Active <span class="hlt">Transport</span> to School (BEATS) Study: protocol for a cross-sectional study</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mandic, Sandra; Williams, John; Moore, Antoni; Hopkins, Debbie; Flaherty, Charlotte; Wilson, Gordon; García Bengoechea, Enrique; Spence, John C</p> <p>2016-01-01</p> <p>Introduction Active <span class="hlt">transport</span> to school (ATS) is a convenient way to increase physical activity and undertake an environmentally sustainable travel practice. The Built <span class="hlt">Environment</span> and Active <span class="hlt">Transport</span> to School (BEATS) Study examines ATS in adolescents in Dunedin, New Zealand, using ecological models for active <span class="hlt">transport</span> that account for individual, social, environmental and policy factors. The study objectives are to: (1) understand the reasons behind adolescents and their parents' choice of <span class="hlt">transport</span> mode to school; (2) examine the interaction between the <span class="hlt">transport</span> choices, built <span class="hlt">environment</span>, physical activity and weight status in adolescents; and (3) identify policies that promote or hinder ATS in adolescents. Methods and analysis The study will use a mixed-method approach incorporating both quantitative (surveys, anthropometry, accelerometers, Geographic Information System (GIS) analysis, mapping) and qualitative methods (focus groups, interviews) to gather data from students, parents, teachers and school principals. The core data will include accelerometer-measured physical activity, anthropometry, GIS measures of the built <span class="hlt">environment</span> and the use of maps indicating route to school (students)/work (parents) and perceived safe/unsafe areas along the route. To provide comprehensive data for understanding how to change the infrastructure to support ATS, the study will also examine complementary variables such as individual, family and social factors, including student and parental perceptions of walking and cycling to school, parental perceptions of different modes of <span class="hlt">transport</span> to school, perceptions of the neighbourhood <span class="hlt">environment</span>, route to school (students)/work (parents), perceptions of driving, use of information communication technology, reasons for choosing a particular school and student and parental physical activity habits, screen time and weight status. The study has achieved a 100% school recruitment rate (12 secondary schools). Ethics and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ChPhB..25j5201L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ChPhB..25j5201L"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> of Lorentz plasma with collision and magnetic field effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lv, Chong; Wan, Feng; Jia, Mo-Ran; Li, Zi-Liang; Sang, Hai-Bo; Xie, Bai-Song</p> <p>2016-10-01</p> <p>The <span class="hlt">electronic</span> transverse <span class="hlt">transport</span> of Lorentz plasma with collision and magnetic field effects is studied by solving the Boltzmann equation for different <span class="hlt">electron</span> density distributions. For the Maxwellian distribution, it is shown that <span class="hlt">transport</span> coefficients decrease as Ω increases, Ω is the ratio of an electron’s magneto-cyclotron frequency to plasma collision frequency. It means that the <span class="hlt">electrons</span> are possible to be highly collimated by a strong magnetic field. For the quasi-monoenergetic distribution with different widths, it is found that the <span class="hlt">transport</span> coefficients decrease greatly as ɛ¯ decreases. In particular when the width approaches to zero the transverse <span class="hlt">transport</span> coefficients are hardly affected by the magnetic field and the minimal one is obtained. Results imply that the strong magnetic field and quasi-monoenergetic distribution are both beneficial to reduce the <span class="hlt">electronic</span> transverse <span class="hlt">transport</span>. This study is also helpful to understand the relevant problems of plasma <span class="hlt">transport</span> in the background of the inertial confinement fusion. Project supported by the National Natural Science Foundation of China (Grant Nos. 11475026 and 11305010) and the NSAF of China (Grant No. U1530153).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22391741','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22391741"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> properties of one dimensional lithium nanowire using density functional theory</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Thakur, Anil; Kumar, Arun; Chandel, Surjeet; Ahluwalia, P. K.</p> <p>2015-05-15</p> <p>Single nanowire electrode devices are a unique platform for studying as energy storage devices. Lithium nanowire is of much importance in lithium ion batteries and therefore has received a great deal of attention in past few years. In this paper we investigated structural and <span class="hlt">electronic</span> <span class="hlt">transport</span> properties of Li nanowire using density functional theory (DFT) with SIESTA code. <span class="hlt">Electronic</span> <span class="hlt">transport</span> properties of Li nanowire are investigated theoretically. The calculations are performed in two steps: first an optimized geometry for Li nanowire is obtained using DFT calculations, and then the <span class="hlt">transport</span> relations are obtained using NEGF approach. SIESTA and TranSIESTA simulation codes are used in the calculations correspondingly. The electrodes are chosen to be the same as the central region where <span class="hlt">transport</span> is studied, eliminating current quantization effects due to contacts and focusing the <span class="hlt">electronic</span> <span class="hlt">transport</span> study to the intrinsic structure of the material. By varying chemical potential in the electrode regions, an I-V curve is traced which is in agreement with the predicted behavior. Agreement of bulk properties of Li with experimental values make the study of <span class="hlt">electronic</span> and <span class="hlt">transport</span> properties in lithium nanowires interesting because they are promising candidates as bridging pieces in nanoelectronics. Transmission coefficient and V-I characteristic of Li nano wire indicates that Li nanowire can be used as an electrode device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25050525','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25050525"><span id="translatedtitle">Centimeter-long <span class="hlt">electron</span> <span class="hlt">transport</span> in marine sediments via conductive minerals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Malvankar, Nikhil S; King, Gary M; Lovley, Derek R</p> <p>2015-02-01</p> <p>Centimeter-long <span class="hlt">electron</span> conduction through marine sediments, in which <span class="hlt">electrons</span> derived from sulfide in anoxic sediments are <span class="hlt">transported</span> to oxygen in surficial sediments, may have an important influence on sediment geochemistry. Filamentous bacteria have been proposed to mediate the <span class="hlt">electron</span> <span class="hlt">transport</span>, but the filament conductivity could not be verified and other mechanisms are possible. Surprisingly, previous investigations have never actually measured the sediment conductivity or its basic physical properties. Here we report direct measurements that demonstrate centimeter-long <span class="hlt">electron</span> flow through marine sediments, with conductivities sufficient to account for previously estimated <span class="hlt">electron</span> fluxes. Conductivity was lost for oxidized sediments, which contrasts with the previously described increase in the conductivity of microbial biofilms upon oxidation. Adding pyrite to the sediments significantly enhanced the conductivity. These results suggest that the role of conductive minerals, which are more commonly found in sediments than centimeter-long microbial filaments, need to be considered when modeling marine sediment biogeochemistry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19778138','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19778138"><span id="translatedtitle">Vibration-induced inelastic effects in the <span class="hlt">electron</span> <span class="hlt">transport</span> through multisite molecular bridges.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zimbovskaya, Natalya A; Kuklja, Maija M</p> <p>2009-09-21</p> <p>We theoretically analyzed inelastic effects in the <span class="hlt">electron</span> <span class="hlt">transport</span> through molecular junctions originating from <span class="hlt">electron</span>-vibron interactions. The molecular bridge was simulated by a periodical chain of identical hydrogenlike atoms with the nearest neighbors interaction thus providing a set of energy states for the <span class="hlt">electron</span> tunneling. To avoid difficulties inevitably arising when advanced computational techniques are employed to study inelastic <span class="hlt">electron</span> <span class="hlt">transport</span> through multilevel bridges, we propose and develop a semiphenomenological approach. The latter is based on Buttiker's dephasing model within the scattering matrix formalism. We apply the proposed approach to describe features associated with <span class="hlt">electron</span> energy transfer to vibrational phonons that appear in the second derivative of the current in the junction with respect to the bias voltage. In the particular case of a single level bridge our results agree with those obtained by proper calculations carried out within the nonequilibrium Green's functions method indicating the usefulness of the suggested approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAP...117v5101B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAP...117v5101B"><span id="translatedtitle">Theoretical study of <span class="hlt">electronic</span> <span class="hlt">transport</span> properties of a graphene-silicene bilayer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berdiyorov, G. R.; Bahlouli, H.; Peeters, F. M.</p> <p>2015-06-01</p> <p><span class="hlt">Electronic</span> <span class="hlt">transport</span> properties of a graphene-silicene bilayer system are studied using density-functional theory in combination with the nonequilibrium Green's function formalism. Depending on the energy of the <span class="hlt">electrons</span>, the transmission can be larger in this system as compared to the sum of the transmissions of separated graphene and silicene monolayers. This effect is related to the increased <span class="hlt">electron</span> density of states in the bilayer sample. At some energies, the <span class="hlt">electronic</span> states become localized in one of the layers, resulting in the suppression of the <span class="hlt">electron</span> transmission. The effect of an applied voltage on the transmission becomes more pronounced in the layered sample as compared to graphene due to the larger variation of the electrostatic potential profile. Our findings will be useful when creating hybrid nanoscale devices where enhanced <span class="hlt">transport</span> properties will be desirable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22412929','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22412929"><span id="translatedtitle">Theoretical study of <span class="hlt">electronic</span> <span class="hlt">transport</span> properties of a graphene-silicene bilayer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Berdiyorov, G. R.; Bahlouli, H.; Peeters, F. M.</p> <p>2015-06-14</p> <p><span class="hlt">Electronic</span> <span class="hlt">transport</span> properties of a graphene-silicene bilayer system are studied using density-functional theory in combination with the nonequilibrium Green's function formalism. Depending on the energy of the <span class="hlt">electrons</span>, the transmission can be larger in this system as compared to the sum of the transmissions of separated graphene and silicene monolayers. This effect is related to the increased <span class="hlt">electron</span> density of states in the bilayer sample. At some energies, the <span class="hlt">electronic</span> states become localized in one of the layers, resulting in the suppression of the <span class="hlt">electron</span> transmission. The effect of an applied voltage on the transmission becomes more pronounced in the layered sample as compared to graphene due to the larger variation of the electrostatic potential profile. Our findings will be useful when creating hybrid nanoscale devices where enhanced <span class="hlt">transport</span> properties will be desirable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012APS..MAR.S1260R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012APS..MAR.S1260R&link_type=ABSTRACT"><span id="translatedtitle">Dependence of magnetic field and <span class="hlt">electronic</span> <span class="hlt">transport</span> of Mn4 Single-molecule magnet in a Single-<span class="hlt">Electron</span> Transistor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rodriguez, Alvar; Singh, Simranjeet; Haque, Firoze; Del Barco, Enrique; Nguyen, Tu; Christou, George</p> <p>2012-02-01</p> <p>Dependence of magnetic field and <span class="hlt">electronic</span> <span class="hlt">transport</span> of Mn4 Single-molecule magnet in a Single-<span class="hlt">Electron</span> Transistor A. Rodriguez, S. Singh, F. Haque and E. del Barco Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, Florida 32816 USA T. Nguyen and G. Christou Department of Chemistry, University of Florida, Gainesville, Florida 32611 USA Abstract We have performed single-<span class="hlt">electron</span> <span class="hlt">transport</span> measurements on a series of Mn-based low-nuclearity single-molecule magnets (SMM) observing Coulomb blockade. SMMs with well isolated and low ground spin states, i.e. S = 9/2 (Mn4) and S = 6 (Mn3) were chosen for these studies, such that the ground spin multiplet does not mix with levels of other excited spin states for the magnetic fields (H = 0-8 T) employed in the experiments. Different functionalization groups were employed to change the mechanical, geometrical and <span class="hlt">transport</span> characteristics of the molecules when deposited from liquid solution on the transistors. Electromigration-broken three-terminal single-<span class="hlt">electron</span> transistors were used. Results obtained at temperatures down to 240 mK and in the presence of high magnetic fields will be shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED562393.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED562393.pdf"><span id="translatedtitle">What Do Context Aware <span class="hlt">Electronic</span> Alerts from Virtual Learning <span class="hlt">Environments</span> Tell Us about User Time & Location?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Crane, Laura; Benachour, Phillip</p> <p>2013-01-01</p> <p>The paper describes the analysis of user location and time stamp information automatically logged when students receive and interact with <span class="hlt">electronic</span> updates from the University's virtual learning <span class="hlt">environment</span>. The <span class="hlt">electronic</span> updates are sent to students' mobile devices using RSS feeds. The mobile reception of such information can be received in…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934278','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934278"><span id="translatedtitle">Quality Detection of Litchi Stored in Different <span class="hlt">Environments</span> Using an <span class="hlt">Electronic</span> Nose</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Sai; Lü, Enli; Lu, Huazhong; Zhou, Zhiyan; Wang, Yu; Yang, Jing; Wang, Yajuan</p> <p>2016-01-01</p> <p>The purpose of this paper was to explore the utility of an <span class="hlt">electronic</span> nose to detect the quality of litchi fruit stored in different <span class="hlt">environments</span>. In this study, a PEN3 <span class="hlt">electronic</span> nose was adopted to test the storage time and hardness of litchi that were stored in three different types of <span class="hlt">environment</span> (room temperature, refrigerator and controlled-atmosphere). After acquiring data about the hardness of the sample and from the <span class="hlt">electronic</span> nose, linear discriminant analysis (LDA), canonical correlation analysis (CCA), BP neural network (BPNN) and BP neural network-partial least squares regression (BPNN-PLSR), were employed for data processing. The experimental results showed that the hardness of litchi fruits stored in all three <span class="hlt">environments</span> decreased during storage. The litchi stored at room temperature had the fastest rate of decrease in hardness, followed by those stored in a refrigerator <span class="hlt">environment</span> and under a controlled-atmosphere. LDA has a poor ability to classify the storage time of the three <span class="hlt">environments</span> in which litchi was stored. BPNN can effectively recognize the storage time of litchi stored in a refrigerator and a controlled-atmosphere <span class="hlt">environment</span>. However, the BPNN classification of the effect of room temperature storage on litchi was poor. CCA results show a significant correlation between <span class="hlt">electronic</span> nose data and hardness data under the room temperature, and the correlation is more obvious for those under the refrigerator <span class="hlt">environment</span> and controlled-atmosphere <span class="hlt">environment</span>. The BPNN-PLSR can effectively predict the hardness of litchi under refrigerator storage conditions and a controlled-atmosphere <span class="hlt">environment</span>. However, the BPNN-PLSR prediction of the effect of room temperature storage on litchi and global <span class="hlt">environment</span> storage on litchi were poor. Thus, this experiment proved that an <span class="hlt">electronic</span> nose can detect the quality of litchi under refrigeratored storage and a controlled-atmosphere <span class="hlt">environment</span>. These results provide a useful reference for future</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1048508','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1048508"><span id="translatedtitle">Adaptations in <span class="hlt">Electronic</span> Structure Calculations in Heterogeneous <span class="hlt">Environments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Talamudupula, Sai</p> <p>2011-01-01</p> <p>Modern quantum chemistry deals with <span class="hlt">electronic</span> structure calculations of unprecedented complexity and accuracy. They demand full power of high-performance computing and must be in tune with the given architecture for superior e ciency. To make such applications resourceaware, it is desirable to enable their static and dynamic adaptations using some external software (middleware), which may monitor both system availability and application needs, rather than mix science with system-related calls inside the application. The present work investigates scienti c application interlinking with middleware based on the example of the computational chemistry package GAMESS and middleware NICAN. The existing synchronous model is limited by the possible delays due to the middleware processing time under the sustainable runtime system conditions. Proposed asynchronous and hybrid models aim at overcoming this limitation. When linked with NICAN, the fragment molecular orbital (FMO) method is capable of adapting statically and dynamically its fragment scheduling policy based on the computing platform conditions. Signi cant execution time and throughput gains have been obtained due to such static adaptations when the compute nodes have very di erent core counts. Dynamic adaptations are based on the main memory availability at run time. NICAN prompts FMO to postpone scheduling certain fragments, if there is not enough memory for their immediate execution. Hence, FMO may be able to complete the calculations whereas without such adaptations it aborts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014BpRL....9..397R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014BpRL....9..397R"><span id="translatedtitle">Single-File <span class="hlt">Transport</span> of Classical <span class="hlt">Electrons</span> on the Surface of Liquid Helium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rees, David G.; Kono, Kimitoshi</p> <p>2014-07-01</p> <p><span class="hlt">Electrons</span> trapped on the surface of liquid helium form a model two-dimensional system. Because the <span class="hlt">electron</span> density is low ( 109 cm-2) and the Coulomb interaction between the <span class="hlt">electrons</span> is essentially unscreened, the system can be regarded as a classical analogue of the degenerate Fermi gas. <span class="hlt">Electrons</span> on helium have therefore long been used to study many-body <span class="hlt">transport</span> phenomena in two dimensions. Here we review recent experiments investigating the <span class="hlt">transport</span> of <span class="hlt">electrons</span> on helium through microscopic constrictions formed in microchannel devices. Two constriction geometries are studied; short saddle-point constrictions and long constrictions in which the length greatly exceeds the width. In both cases, the constriction width can be tuned electrostatically so that the <span class="hlt">electrons</span> move in single file. As the width of the short constriction is increased, a periodic suppression of the <span class="hlt">electron</span> current is observed due to pinning for commensurate states of the <span class="hlt">electron</span> lattice. A related phenomenon is observed for the long constriction whereby the quasi-one-dimensional Wigner lattice exhibits reentrant melting as the number of <span class="hlt">electron</span> chains increases. Our results demonstrate that <span class="hlt">electrons</span> on helium are an ideal system in which to study many-body <span class="hlt">transport</span> in the limit of single-file motion. Special Issue Comments: This article presents experimental results on the dynamics of classical <span class="hlt">electrons</span> moving on the surface of liquid helium in narrow channels with constrictions, with a focus on the "quantum wire", i.e. single file, regime. This article is related to the Special Issue articles about advanced statistical properties in single file dynamics34 and the mathematical results on <span class="hlt">electron</span> dynamics in liquid helium.35</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22264075','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22264075"><span id="translatedtitle">Quantum <span class="hlt">transport</span> through disordered 1D wires: Conductance via localized and delocalized <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gopar, Víctor A.</p> <p>2014-01-14</p> <p>Coherent <span class="hlt">electronic</span> <span class="hlt">transport</span> through disordered systems, like quantum wires, is a topic of fundamental and practical interest. In particular, the exponential localization of <span class="hlt">electron</span> wave functions-Anderson localization-due to the presence of disorder has been widely studied. In fact, Anderson localization, is not an phenomenon exclusive to <span class="hlt">electrons</span> but it has been observed in microwave and acoustic experiments, photonic materials, cold atoms, etc. Nowadays, many properties of <span class="hlt">electronic</span> <span class="hlt">transport</span> of quantum wires have been successfully described within a scaling approach to Anderson localization. On the other hand, anomalous localization or delocalization is, in relation to the Anderson problem, a less studied phenomenon. Although one can find signatures of anomalous localization in very different systems in nature. In the problem of <span class="hlt">electronic</span> <span class="hlt">transport</span>, a source of delocalization may come from symmetries present in the system and particular disorder configurations, like the so-called Lévy-type disorder. We have developed a theoretical model to describe the statistical properties of <span class="hlt">transport</span> when <span class="hlt">electron</span> wave functions are delocalized. In particular, we show that only two physical parameters determine the complete conductance distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19278211','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19278211"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> on the nanoscale: ballistic transmission and Ohm's law.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Homoth, J; Wenderoth, M; Druga, T; Winking, L; Ulbrich, R G; Bobisch, C A; Weyers, B; Bannani, A; Zubkov, E; Bernhart, A M; Kaspers, M R; Möller, R</p> <p>2009-04-01</p> <p>If a current of <span class="hlt">electrons</span> flows through a normal conductor (in contrast to a superconductor), it is impeded by local scattering at defects as well as phonon scattering. Both effects contribute to the voltage drop observed for a macroscopic complex system as described by Ohm's law. Although this concept is well established, it has not yet been measured around individual defects on the atomic scale. We have measured the voltage drop at a monatomic step in real space by restricting the current to a surface layer. For the Si(111)-( [see text]3 x [see text]3)-Ag surface a monotonous transition with a width below 1 nm was found. A numerical analysis of the data maps the current flow through the complex network and the interplay between defect-free terraces and monatomic steps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26508279','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26508279"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> properties of Ir-decorated graphene.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yilin; Xiao, Shudong; Cai, Xinghan; Bao, Wenzhong; Reutt-Robey, Janice; Fuhrer, Michael S</p> <p>2015-10-28</p> <p>Graphene decorated with 5d transitional metal atoms is predicted to exhibit many intriguing properties; for example iridium adatoms are proposed to induce a substantial topological gap in graphene. We extensively investigated the conductivity of single-layer graphene decorated with iridium deposited in ultra-high vacuum at low temperature (7 K) as a function of Ir concentration, carrier density, temperature, and annealing conditions. Our results are consistent with the formation of Ir clusters of ~100 atoms at low temperature, with each cluster donating a single <span class="hlt">electronic</span> charge to graphene. Annealing graphene increases the cluster size, reducing the doping and increasing the mobility. We do not observe any sign of an energy gap induced by spin-orbit coupling, possibly due to the clustering of Ir.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT.......116R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT.......116R"><span id="translatedtitle"><span class="hlt">Electronic</span> structure and quantum <span class="hlt">transport</span> in controlled impurity systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ryu, Hoon</p> <p></p> <p>Due to a continuous device downscaling, a precise control of dopant placements has become a critical factor to determine device performances. Recent progresses in the Scanning Tunneling Microscope lithography control dopant positions within a few atomic layers and have led experimentalists to propose various prototypes of planar patterned densely phosphorous delta-doping silicon (Si:P) devices. Theoretical understanding of <span class="hlt">electronic</span> properties in such systems based on a realistic modeling approach is critical for potential device designs. Si:P devices are studied with the atomistic tight-binding (TB) approach coupled to charge-potential self-consistent simulations. The dispersion of a 1/4 mono-layer (ML) doped Si:P doping plane is simulated and compared to the previous literatures to validate our methodology. Upon the methodological validation, dispersions of 1/4ML doped ultra-narrow nanowires (NWs) are studied to explain experimentally observed metallic properties. Predicted channel conductances agree well with measured values. Then, a single donor quantum dot device with Si:P NW leads, is modeled to confirm the experimentally realized device is indeed a single atom transistor. Predicted charging energy and gate-control over the channel ground state establish strong connections to the experimental results. Finally, the numerical practicality of the Contact Block Reduction (CBR) method in simulating <span class="hlt">electron</span> resonance tunneling features, is examined using Si:P NWs as examples. Based on a proof of principles on small TB systems, we show the CBR method can be practical on supercomputing clusters, due a better scalability than the one observed from the Recursive Greens Function and Wavefunction algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22212732','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22212732"><span id="translatedtitle">Monte Carlo <span class="hlt">electron</span>-photon <span class="hlt">transport</span> using GPUs as an accelerator: Results for a water-aluminum-water phantom</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Su, L.; Du, X.; Liu, T.; Xu, X. G.</p> <p>2013-07-01</p> <p>An <span class="hlt">electron</span>-photon coupled Monte Carlo code ARCHER - Accelerated Radiation-<span class="hlt">transport</span> Computations in Heterogeneous <span class="hlt">Environments</span> - is being developed at Rensselaer Polytechnic Institute as a software test bed for emerging heterogeneous high performance computers that utilize accelerators such as GPUs. In this paper, the preliminary results of code development and testing are presented. The <span class="hlt">electron</span> <span class="hlt">transport</span> in media was modeled using the class-II condensed history method. The <span class="hlt">electron</span> energy considered ranges from a few hundred keV to 30 MeV. Moller scattering and bremsstrahlung processes above a preset energy were explicitly modeled. Energy loss below that threshold was accounted for using the Continuously Slowing Down Approximation (CSDA). Photon <span class="hlt">transport</span> was dealt with using the delta tracking method. Photoelectric effect, Compton scattering and pair production were modeled. Voxelised geometry was supported. A serial ARHCHER-CPU was first written in C++. The code was then ported to the GPU platform using CUDA C. The hardware involved a desktop PC with an Intel Xeon X5660 CPU and six NVIDIA Tesla M2090 GPUs. ARHCHER was tested for a case of 20 MeV <span class="hlt">electron</span> beam incident perpendicularly on a water-aluminum-water phantom. The depth and lateral dose profiles were found to agree with results obtained from well tested MC codes. Using six GPU cards, 6x10{sup 6} histories of <span class="hlt">electrons</span> were simulated within 2 seconds. In comparison, the same case running the EGSnrc and MCNPX codes required 1645 seconds and 9213 seconds, respectively, on a CPU with a single core used. (authors)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005PhRvB..71o5310F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005PhRvB..71o5310F&link_type=ABSTRACT"><span id="translatedtitle">Two-band <span class="hlt">electron</span> <span class="hlt">transport</span> in a double quantum well</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fletcher, R.; Tsaousidou, M.; Smith, T.; Coleridge, P. T.; Wasilewski, Z. R.; Feng, Y.</p> <p>2005-04-01</p> <p>The carrier densities and mobilities have been measured for the first two populated subbands in a GaAs double quantum well (DQW) as a function of the top gate voltage Vg . The densities and quantum mobilities ( μiq , i=1,2 ) were obtained from the de Haas-Shubnikov oscillations. The <span class="hlt">transport</span> mobilities (μit) were determined from the semiclassical low-field magnetoresistance with intersubband scattering taken into account. At 0.32K the experimental data on both μit and μiq , as a function of Vg , lie on two curves which cross at the resonance point as expected from theoretical considerations. At 1.09K and 4.2K the μit curves no longer cross at resonance, but show a gap. The reason for this is not known. The mobilities have been calculated in the low-temperature limit within the Boltzmann framework by assuming that they are limited by scattering due to ionized impurities located at the outside interfaces. The assumption of short-range scattering is justified by the relatively small value of the ratio μit/μiq that is measured in the present system. The theoretical values obtained for μit and μiq are in reasonable agreement with the experiment for all values of Vg examined. We have also calculated the resistivity and intersubband scattering rates of the DQW as a function of Vg and again find good agreement with measured values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JAP...104b4302M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JAP...104b4302M"><span id="translatedtitle">Experimental investigation of <span class="hlt">electron</span> <span class="hlt">transport</span> properties of gallium nitride nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Motayed, Abhishek; Davydov, Albert V.; Mohammad, S. N.; Melngailis, John</p> <p>2008-07-01</p> <p>We report <span class="hlt">transport</span> properties of gallium nitride (GaN) nanowires grown using direct reaction of ammonia and gallium vapor. Reliable devices, such as four-terminal resistivity measuring structures and field-effect transistors, were realized by dielectrophoretically aligning the nanowires on an oxidized silicon substrate and subsequently applying standard microfabrication techniques. Room-temperature resistivity in the range of (1.0-6.2)×10-2 Ω cm was obtained for the nanowires with diameters ranging from 200 to 90 nm. Temperature-dependent resistivity and mobility measurements indicated the possible sources for the n-type conductivity and high background charge carrier concentration in these nanowires. Specific contact resistance in the range of 5.0×10-5 Ω cm2 was extracted for Ti/Al/Ti/Au metal contacts to GaN nanowires. Significant reduction in the activation energy of the dopants at low temperatures (<200 K) was observed in the temperature-dependent resistivity measurement of these nanowires, which is linked to the onset of degeneracy. Temperature-dependent field-effect mobility measurements indicated that the ionized impurity scattering is the dominant mechanism in these nanowires at all temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhyE...17..272A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhyE...17..272A"><span id="translatedtitle">Non-equilibrium <span class="hlt">electron</span> <span class="hlt">transport</span> in degenerate nitride heterostructures-dynamic screening effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anderson, D. R.; Babiker, M.; Bennett, C. R.; Probert, M. I. J.</p> <p>2003-04-01</p> <p>We show how dynamic screening effects on non-equilibrium <span class="hlt">electron</span> <span class="hlt">transport</span> can be incorporated in the case of <span class="hlt">electronically</span> dense GaN-based quantum wells. The theory is based on the Boltzmann equation, leading to evaluations of the momentum relaxation time and, hence, the <span class="hlt">electron</span> mobility in these heterostructures. We find that both screening and anti-screening effects are manifest as the <span class="hlt">electron</span> density varies. However, anti-screening dominates over a wide range of densities, with screening commencing at densities appropriate for phonon-plasmon coupling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22408372','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22408372"><span id="translatedtitle">Influence of oblique magnetic field on <span class="hlt">electron</span> cross-field <span class="hlt">transport</span> in a Hall effect thruster</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Miedzik, Jan; Daniłko, Dariusz; Barral, Serge</p> <p>2015-04-15</p> <p>The effects of the inclination of the magnetic field with respect to the channel walls in a Hall effect thruster are numerically studied with the use of a one-dimensional quasi-neutral Particle-In-Cell model with guiding center approximation of <span class="hlt">electron</span> motion along magnetic lines. Parametric studies suggest that the incidence angle strongly influences <span class="hlt">electron</span> <span class="hlt">transport</span> across the magnetic field. In ion-focusing magnetic topologies, <span class="hlt">electrons</span> collide predominantly on the side of the magnetic flux tube closer to the anode, thus increasing the <span class="hlt">electron</span> cross-field drift. The opposite effect is observed in ion-defocussing topology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20931122','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20931122"><span id="translatedtitle">Characteristics and <span class="hlt">transport</span> of organochlorine pesticides in urban <span class="hlt">environment</span>: air, dust, rain, canopy throughfall, and runoff.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Wei; Ye, Youbin; Hu, Dan; Ou, Langbo; Wang, Xuejun</p> <p>2010-11-01</p> <p>Characteristics and <span class="hlt">transport</span> of organochlorine pesticides (OCPs) in urban multiple <span class="hlt">environments</span>, including air, dust, rain, canopy throughfall, and runoff water, are explored in this study. Hexachlorocyclohexanes (HCHs) dominated in both air and rain water, and dichlorodiphenyltrichloroethane (DDT) related substances showed a higher affinity to dust. Relatively high concentrations of DDT and dichlorodiphenyldichloroethylene (DDE) in air, rain and dust imply that technical DDT in the <span class="hlt">environment</span> has been degrading, and there may be unknown local or regional emission sources that contain DDTs in the study area. Source identification showed that DDTs in Beijing urban <span class="hlt">environments</span> with a fresh signature may originate from the atmospheric <span class="hlt">transport</span> from remote areas. The ratio of α-/γ-HCH in dust, rain, canopy throughfall and runoff were close to 1, indicating the possible use of lindane. OCPs in runoff were <span class="hlt">transported</span> from various sources including rain, dust, and canopy throughfall. In runoff, DDTs and hexachlorobenzene (HCB) were mainly <span class="hlt">transported</span> from dust, and HCHs were mainly from rain and canopy throughfall.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11102017','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11102017"><span id="translatedtitle">Experimental evidence of electric inhibition in fast <span class="hlt">electron</span> penetration and of electric-field-limited fast <span class="hlt">electron</span> <span class="hlt">transport</span> in dense matter</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pisani; Bernardinello; Batani; Antonicci; Martinolli; Koenig; Gremillet; Amiranoff; Baton; Davies; Hall; Scott; Norreys; Djaoui; Rousseaux; Fews; Bandulet; Pepin</p> <p>2000-11-01</p> <p>Fast <span class="hlt">electron</span> generation and propagation were studied in the interaction of a green laser with solids. The experiment, carried out with the LULI TW laser (350 fs, 15 J), used K(alpha) emission from buried fluorescent layers to measure <span class="hlt">electron</span> <span class="hlt">transport</span>. Results for conductors (Al) and insulators (plastic) are compared with simulations: in plastic, inhibition in the propagation of fast <span class="hlt">electrons</span> is observed, due to electric fields which become the dominant factor in <span class="hlt">electron</span> <span class="hlt">transport</span>. PMID:11102017</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MAR.Y8012T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MAR.Y8012T"><span id="translatedtitle">Effects of Surface Roughness and <span class="hlt">Electron</span>-Phonon Interaction on <span class="hlt">Electron</span> <span class="hlt">Transport</span> of Ultrathin Epitaxial Copper Films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Timalsina, Yukta; Horning, Andrew; Spivey, Robert; Lewis, Kim; Wang, Gwo-Ching; Lu, Toh-Ming</p> <p>2015-03-01</p> <p>We report effects of surface roughness and <span class="hlt">electron</span>-phonon interaction on <span class="hlt">transport</span> properties of <span class="hlt">electrons</span> in ultrathin epitaxial copper films of thickness ranging from 5 nm to 500 nm grown on Si(100) substrates. The <span class="hlt">transport</span> of <span class="hlt">electrons</span> in the film was examined by measuring the temperature dependent resistivity in the temperature range of 5 K to 300 K. We demonstrate that the temperature independent component of resistivity can be described by the root-mean-square-surface roughness and lateral correlation length with no adjustable parameter, using a recent quasi-classical model developed by Chatterjee and Meyerovich. However, the temperature dependent component of the resistivity can be described using the Bloch-Grüneisen formula with a thickness dependent <span class="hlt">electron</span>-phonon coupling constant and a thickness dependent Debye temperature. We show that the increase of the <span class="hlt">electron</span>-phonon coupling constant with the decrease of film thickness gives rise to an enhancement of the temperature dependent component of the resistivity. This work is supported in part by New York State Foundation of Science, Technology and Innovation through Focus Center-New York.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26538036','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26538036"><span id="translatedtitle">Plasmon-Mediated <span class="hlt">Electron</span> <span class="hlt">Transport</span> in Tip-Enhanced Raman Spectroscopic Junctions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pal, Partha Pratim; Jiang, Nan; Sonntag, Matthew D; Chiang, Naihao; Foley, Edward T; Hersam, Mark C; Van Duyne, Richard P; Seideman, Tamar</p> <p>2015-11-01</p> <p>We combine experiment, theory, and first-principles-based calculations to study the light-induced plasmon-mediated <span class="hlt">electron</span> <span class="hlt">transport</span> characteristics of a molecular-scale junction. The experimental data show a nonlinear increase in <span class="hlt">electronic</span> current perturbation when the focus of a chopped laser beam moves laterally toward the tip-sample junction. To understand this behavior and generalize it, we apply a combined theory of the <span class="hlt">electronic</span> nonequilibrium formed upon decoherence of an optically triggered plasmon and first-principles <span class="hlt">transport</span> calculations. Our model illustrates that the current via an adsorbed molecular monolayer increases nonlinearly as more energy is pumped into the junction due to the increasing availability of virtual molecular orbital channels for <span class="hlt">transport</span> with higher injection energies. Our results thus illustrate light-triggered, plasmon-enhanced tunneling current in the presence of a molecular linker. PMID:26538036</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyC..525...18Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyC..525...18Z"><span id="translatedtitle"><span class="hlt">Transport</span> anomalies and quantum criticality in <span class="hlt">electron</span>-doped cuprate superconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xu; Yu, Heshan; He, Ge; Hu, Wei; Yuan, Jie; Zhu, Beiyi; Jin, Kui</p> <p>2016-06-01</p> <p>Superconductivity research is like running a marathon. Three decades after the discovery of high-Tc cuprates, there have been mass data generated from <span class="hlt">transport</span> measurements, which bring fruitful information. In this review, we give a brief summary of the intriguing phenomena reported in <span class="hlt">electron</span>-doped cuprates from the aspect of electrical <span class="hlt">transport</span> as well as the complementary thermal <span class="hlt">transport</span>. We attempt to sort out common features of the <span class="hlt">electron</span>-doped family, e.g. the strange metal, negative magnetoresistance, multiple sign reversals of Hall in mixed state, abnormal Nernst signal, complex quantum criticality. Most of them have been challenging the existing theories, nevertheless, a unified diagram certainly helps to approach the nature of <span class="hlt">electron</span>-doped cuprates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23498744','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23498744"><span id="translatedtitle"><span class="hlt">Electron</span> microscopy of flagella, primary cilia, and intraflagellar <span class="hlt">transport</span> in flat-embedded cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rogowski, Michaela; Scholz, Dirk; Geimer, Stefan</p> <p>2013-01-01</p> <p>Intraflagellar <span class="hlt">transport</span> (IFT) is an evolutionarily highly conserved, microtubule-based, bidirectional <span class="hlt">transport</span> system found in eukaryotic cilia/flagella and is indispensable for their assembly, maintenance, and sensory functions. Powered by two different motor complexes, linear arrays of protein particles, called IFT trains, are <span class="hlt">transported</span> from the base to the tip of the cilium/flagellum and back, carrying axonemal precursors to the tip for assembly and turnover products back to the cell body for recycling. The dynamics of IFT can be visualized using various types of live-cell microscopy techniques, but for analyzing the ultrastructure of IFT trains, transmission <span class="hlt">electron</span> microscopy is indispensable. The focus of this chapter is to describe the application of the flat embedding technique to Chlamydomonas reinhardtii and monolayers of mammalian culture cells. Such flat embeddings are well suited for the analysis of the ultrastructure of the IFT system by standard <span class="hlt">electron</span> microscopy and <span class="hlt">electron</span> tomography.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991JPhy1...1..837L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991JPhy1...1..837L"><span id="translatedtitle">Linear <span class="hlt">electronic</span> <span class="hlt">transport</span> in dense plasmas. II. Finite degeneracy contributions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Léger, D.; Deutsch, C.</p> <p>1991-06-01</p> <p>The formalism described in the first paper in this series is hereafter specialized to a thorough investigation of finite degeneracy contributions to thermoelectronic and mechanical <span class="hlt">transport</span> coefficients, conveniently expressed as reduced quantities. Temperature corrections are systematically discussed through the analytical properties of the jellium dielectric function. The Thomas-Fermi one appears as a paradigm of regular behavior at q=2k_F while the Lindhard and its T-dependent extension head a singular class characterized by diverging derivatives. Specific methods are developed for these important cases. Results are presented in terms of analytic expansions in the degeneracy parameter α, and exact expressions for the above-mentioned corrections are derived up to order α2. Finally we display a number of numerical results pertaining to fully ionized proton-helium binary mixtures of Astrophysical interest. The connection of the present formalism and its numerical outputs with other previous treatments is also carefully examined. Le formalisme exposé et détaillé dans le premier article de cette série est ici appliqué à la détermination des contributions de dégénérescence partielle aux coefficients de <span class="hlt">transport</span> thermoélectroniques et mécanique (viscosité), coefficients préalablement exprimés sous forme d'expressions réduites. Les corrections de température finie sont systématiquement analysées en relation avec les propriétés analytiques de la fonction diélectrique du jellium. Alors que celle de Thomas-Fermi fournit l'exemple type de fonction parfaitement régulière en q=2k_F, celle de Lindhard et sa généralisation à T finie sont au contraire caractérisées par des dérivées divergentes en ce point. Des méthodes spécifiques sont développées pour traiter correctement ces cas importants. Nos résultats sont présentés sous forme de développements analytiques en puissance du paramètre de dégénérescence α, et des expressions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4463002','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4463002"><span id="translatedtitle">Microbial <span class="hlt">electron</span> <span class="hlt">transport</span> and energy conservation – the foundation for optimizing bioelectrochemical systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kracke, Frauke; Vassilev, Igor; Krömer, Jens O.</p> <p>2015-01-01</p> <p>Microbial electrochemical techniques describe a variety of emerging technologies that use electrode–bacteria interactions for biotechnology applications including the production of electricity, waste and wastewater treatment, bioremediation and the production of valuable products. Central in each application is the ability of the microbial catalyst to interact with external <span class="hlt">electron</span> acceptors and/or donors and its metabolic properties that enable the combination of <span class="hlt">electron</span> <span class="hlt">transport</span> and carbon metabolism. And here also lies the key challenge. A wide range of microbes has been discovered to be able to exchange <span class="hlt">electrons</span> with solid surfaces or mediators but only a few have been studied in depth. Especially <span class="hlt">electron</span> transfer mechanisms from cathodes towards the microbial organism are poorly understood but are essential for many applications such as microbial electrosynthesis. We analyze the different <span class="hlt">electron</span> <span class="hlt">transport</span> chains that nature offers for organisms such as metal respiring bacteria and acetogens, but also standard biotechnological organisms currently used in bio-production. Special focus lies on the essential connection of redox and energy metabolism, which is often ignored when studying bioelectrochemical systems. The possibility of extracellular <span class="hlt">electron</span> exchange at different points in each organism is discussed regarding required redox potentials and effect on cellular redox and energy levels. Key compounds such as <span class="hlt">electron</span> carriers (e.g., cytochromes, ferredoxin, quinones, flavins) are identified and analyzed regarding their possible role in electrode–microbe interactions. This work summarizes our current knowledge on <span class="hlt">electron</span> <span class="hlt">transport</span> processes and uses a theoretical approach to predict the impact of different modes of transfer on the energy metabolism. As such it adds an important piece of fundamental understanding of microbial <span class="hlt">electron</span> <span class="hlt">transport</span> possibilities to the research community and will help to optimize and advance bioelectrochemical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NucFu..55h3011S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NucFu..55h3011S"><span id="translatedtitle"><span class="hlt">Electron</span> temperature critical gradient and <span class="hlt">transport</span> stiffness in DIII-D</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, S. P.; Petty, C. C.; White, A. E.; Holland, C.; Bravenec, R.; Austin, M. E.; Zeng, L.; Meneghini, O.</p> <p>2015-08-01</p> <p>In a continuing effort to validate turbulent <span class="hlt">transport</span> models, the <span class="hlt">electron</span> energy flux has been probed as a function of <span class="hlt">electron</span> temperature gradient on the DIII-D tokamak. In the scan of gradient, a critical <span class="hlt">electron</span> temperature gradient has been found in the <span class="hlt">electron</span> heat fluxes and stiffness at various radii in L-mode plasmas. The TGLF reduced turbulent <span class="hlt">transport</span> model (Staebler et al 2007 Phys. Plasmas 14 055909) and full gyrokinetic GYRO model (Candy and Waltz 2003 J. Comput. Phys. 186 545) recover the general trend of increasing <span class="hlt">electron</span> energy flux with increasing <span class="hlt">electron</span> temperature gradient scale length, but they do not predict the absolute level of <span class="hlt">transport</span> at all radii and gradients. Comparing the experimental observations of incremental (heat pulse) diffusivity and stiffness to the models’ reveals that TGLF reproduces the trends in increasing diffusivity and stiffness with increasing <span class="hlt">electron</span> temperature gradient scale length with a critical gradient behavior. The critical gradient of TGLF is found to have a dependence on q95, contrary to the independence of the experimental critical gradient from q95.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25757328','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25757328"><span id="translatedtitle">[Environmental behavior of graphene and its effect on the <span class="hlt">transport</span> and fate of pollutants in <span class="hlt">environment</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ren, Wen-Jie; Teng, Ying</p> <p>2014-09-01</p> <p>Graphene is one of the most popular research topics in carbon nanomaterials. Because of its special physical and chemical properties, graphene will have wide applications. As the production and application amount is increasing, graphene will be inevitably released to the <span class="hlt">environment</span>, resulting in risks of ecological <span class="hlt">environment</span> and human health. It is of very vital significance for evaluating environmental risks of graphene scientifically and objectively to understand its environmental behavior and fate and explore its effect on the environmental behaviors of pollutants. This paper reviewed the environmental behavior of graphene, such as colloid properties and its stability in the aqueous <span class="hlt">environment</span> and its <span class="hlt">transport</span> through porous media. Additionally, the paper reviewed the effect of graphene on the <span class="hlt">transport</span> and fate of pollutants. The interactions between graphene and heavy metals or organic compounds were especially discussed. Important topics should be explored including sorption mechanisms, interactions between graphene and soil components, influence of graphene on the <span class="hlt">transport</span> and bioavailability of pollutants in <span class="hlt">environment</span>, as well as approaches to quantifying graphene. The review might identify potential new ideas for further research in applications of graphene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005APS..MARW35007G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005APS..MARW35007G"><span id="translatedtitle">Inelastic <span class="hlt">electron</span> <span class="hlt">transport</span>: IETS, NDR, switching, and hysteresis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galperin, Michael; Nitzan, Abraham; Ratner, Mark</p> <p>2005-03-01</p> <p>We study the effect of the mutual influence between the phonon and the <span class="hlt">electron</span> subsystems using nonequilibrium Green function (NEGF) formalism at the level of self-consistent Born approximation. Regarding the inelastic spectrum, two types of inelastic contributions are discussed. Features associated with real and virtual energy transfer to phonons are usually observed in the second derivative of the current I with respect to the voltage V. Signatures of resonant tunneling driven by an intermediate molecular ion appear as peaks in the first derivative dI/dV and may show phonon sidebands. The dependence of the observed vibrationally induced lineshapes on the junction characteristics, and the linewidths associated with these features are also discussed. Polaron formation on a molecular wire as a possible mechanism for observed NDR, switching and/or hysteresis in the I/V characteristic of molecular junctions is discussed within a simple mean-field model (self-consistent Hartree approximation). This mechanism differs from earlier proposed mechanisms of charging and conformational change. The polaron model captures the essential physics and provides qualitative correspondence with experimental data. The importance of active redox centers in the molecule is indicated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22086022','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22086022"><span id="translatedtitle">Effects of parallel <span class="hlt">electron</span> dynamics on plasma blob <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Angus, Justin R.; Krasheninnikov, Sergei I.; Umansky, Maxim V.</p> <p>2012-08-15</p> <p>The 3D effects on sheath connected plasma blobs that result from parallel <span class="hlt">electron</span> dynamics are studied by allowing for the variation of blob density and potential along the magnetic field line and using collisional Ohm's law to model the parallel current density. The parallel current density from linear sheath theory, typically used in the 2D model, is implemented as parallel boundary conditions. This model includes electrostatic 3D effects, such as resistive drift waves and blob spinning, while retaining all of the fundamental 2D physics of sheath connected plasma blobs. If the growth time of unstable drift waves is comparable to the 2D advection time scale of the blob, then the blob's density gradient will be depleted resulting in a much more diffusive blob with little radial motion. Furthermore, blob profiles that are initially varying along the field line drive the potential to a Boltzmann relation that spins the blob and thereby acts as an addition sink of the 2D potential. Basic dimensionless parameters are presented to estimate the relative importance of these two 3D effects. The deviation of blob dynamics from that predicted by 2D theory in the appropriate limits of these parameters is demonstrated by a direct comparison of 2D and 3D seeded blob simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..MARB20005S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..MARB20005S"><span id="translatedtitle">Coherent <span class="hlt">electron</span> <span class="hlt">transport</span> in InAs nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sourribes, Marion J. L.; Isakov, Ivan; Panfilova, Marina; Ercolani, Daniele; Giazotto, Francesco; Sorba, Lucia; Warburton, Paul A.</p> <p>2013-03-01</p> <p>Indium arsenide nanowires are of special interest since they exhibit high mobility, strong spin-orbit coupling and form ohmic contacts with metals which make them good candidates for the observation of Majorana fermions in semiconductor/superconductor hybrid systems. InAs nanowires have already been used as Josephson elements in superconducting devices. Here we report our low-temperature experiments on InAs nanowires grown by two methods: (i) gold-catalyzed chemical beam epitaxy on InAs (111) substrates; (ii) catalyst-free molecular beam epitaxy on Si (111) substrates. Contacts to the nanowires are defined by e-beam lithography. Before metallization of the contacts, the nanowire surface is deoxidized by an in situ sputter-cleaning process leading to a specific contact resistance of 9 . 8 ×10-9 Ω .cm2. These highly transparent contacts allowed the observation of proximity-induced superconductivity in InAs nanowires connected with Nb contacts. The critical current was tuned by changing the gate voltage. Both magnetic-field-dependent and gate-voltage-dependent measurements of universal conductance fluctuations were performed to extract information on the <span class="hlt">electron</span> phase coherence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2825979','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2825979"><span id="translatedtitle">Proton stoichiometry of <span class="hlt">electron</span> <span class="hlt">transport</span> in rodent tumor mitoplasts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ferreira, J; Reynafarje, B; Costa, L E; Lehninger, A L</p> <p>1988-02-01</p> <p>The mechanistic vectorial H+/O translocation ratios characteristic of energy-conserving sites 2 + 3 and site 3 of the respiratory chain of two tumor cell lines were determined using succinate and ferrocytochrome c, respectively, as <span class="hlt">electron</span> donors. The measurements were carried out on mitoplasts in order to allow ferrocytochrome c free access to its binding site on the inner mitochondrial membrane. The tumor cell lines used were Ehrlich ascites tumor and the AS30-D ascites tumor. K+ was used as charge-compensating cation in the presence of valinomycin. The O2 uptake rate measurements were made with a fast-responding membrane-less electrode whose response time was closely matched with that of a pH electrode. The rates of O2 uptake and H+ ejection during the apparent zero-order rate phase of respiration, analyzed by computer, were extrapolated to zero time. The observed H+/O ratios for succinate oxidation in both tumors exceeded 7 and approached 8 and the H+/O ratios for the cytochrome oxidase reaction closely approached 4.0, in agreement with data or normal mitochondria. However, the rates of H+ back decay in the tumor mitochondria are relatively high and may influence the net efficiency of oxidative phosphorylation under intracellular conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26574382','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26574382"><span id="translatedtitle">Proton Dynamics on Goethite Nanoparticles and Coupling to <span class="hlt">Electron</span> <span class="hlt">Transport</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zarzycki, Piotr; Smith, Dayle M; Rosso, Kevin M</p> <p>2015-04-14</p> <p>The surface chemistry of metal oxide particles is governed by the charge that develops at the interface with aqueous solution. Mineral transformation, biogeochemical reactions, remediation, and sorption dynamics are profoundly affected in response. Here we report implementation of replica-exchange constant-pH molecular dynamics simulations that use classical molecular dynamics for exploring configurational space and Metropolis Monte Carlo walking through protonation space with a simulated annealing escape route from metastable configurations. By examining the archetypal metal oxide, goethite (α-FeOOH), we find that electrostatic potential gradients spontaneously arise between intersecting low-index crystal faces and across explicitly treated oxide nanoparticles at a magnitude exceeding the Johnson-Nyquist voltage fluctuation. Fluctuations in adsorbed proton density continuously repolarize the surface potential bias between edge-sharing crystal faces, at a rate slower than the reported <span class="hlt">electron</span>-polaron hopping rate in goethite interiors. This suggests that these spontaneous surface potential fluctuations will control the net movement of charge carriers in the lattice. PMID:26574382</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARW16011L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARW16011L"><span id="translatedtitle"><span class="hlt">Electronic</span> <span class="hlt">transport</span> in graphene structure: from weak to strong localization regimes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lherbier, Aurelien</p> <p>2015-03-01</p> <p>Graphene, often named the wonder material for its many fascinating properties, has sparked out intense research activities over the last decade. <span class="hlt">Electronic</span> <span class="hlt">transport</span> in graphene became rapidly an important research field because of the early reported extremely high charge carrier mobility which triggered large expectations for nanoelectronic devices. Besides mobilities, graphene samples can exhibit particularly long <span class="hlt">electronic</span> coherence lengths which allow for phase-related quantum <span class="hlt">transport</span> phenomena such as the weak and strong localization <span class="hlt">transport</span> regimes. This makes graphene a remarkable playground for fundamental studies of localization theory in low-dimensional systems. In this presentation, using tight-binding models enriched by first principle calculations, and a real-space Kubo-Greenwood method, multiscale simulations of the <span class="hlt">electronic</span> <span class="hlt">transport</span> in various graphene-based systems will be discussed. Such an approach allows for computing <span class="hlt">transport</span> properties of systems containing millions of atoms reaching therefore the experimental sample size. In order to tailor graphene properties, chemical and/or structural modifications are widely used. However, such modifications act as scattering defects and usually deteriorate <span class="hlt">transport</span> properties. Open a band gap while maintaining good mobility is a typical illustration of this dual problem. The influence of various chemical and structural defects will be analyzed. In particular, the consequences of unbalanced sublattice nitrogen doping in graphene and the case of highly defective graphene structures exhibiting strong Anderson insulator behaviors will be examined. Defects being even more detrimental for <span class="hlt">transport</span> in 1D structures, a synthesis method that is free of defects is highly desirable. A solution is provided by a bottom-up chemistry approach where precursor monomers are self-assembled. The <span class="hlt">electronic</span> <span class="hlt">transport</span> and the potential for nanoelectronics of such defect-free carbon ribbons will also be discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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